What are some good, low-budget telescopes for astrophotography?

I'm looking at getting a telescope so I can do some astrophotography with my DSLR. But I'm really stumped on what I should get. I'd like to get a GoTo Telescope, which tracks and finds objects for you so you don't have to manually find it yourself. I'd like something that would be able to capture planets of our solar system, nebulas, and galaxies. It must be able to support the weight of my DSLR, which is a Nikon D800. I do not want to spend a bunch of money on a telescope, so I'm looking at cheaper options. I want to make sure that I enjoy it and/or can figure out how to do it before dropping money on a nice, more expensive telescope. I'd prefer not to spend more than $500.

I have been looking at this telescope. Any opinions on it?

https://optcorp.com/collections/meade-starnavigator-next-generation-telescopes/products/meade-starnavigator-next-generation-114mm-reflector

I know very little about telescopes so any information would be greatly appreciated.

The Meade 114 alt-azimuth GoTo is not that great for anything but casual views of brighter objects and maybe moon photos, sun photos with safe solar filter film. Maybe planets would appear as bright dots in camera. Stars and faint stuff? NO WAY. This is why:
See the flat joint at top of the tripod? See the dial at the side of the tube of scope? These are at parallel to ground and right angles to ground. They are the motorized axles of what is called an alt-azimuth mounted scope. It sweeps around horizontally, and elevates vertically like a cannon. This is fine for pointing at the sky and using a computer drive to follow an object. BUT.
The sky moves in great arc motion around the celestial poles The only three spots on Earth where an alt-azimuth mount will follow for astro photo time exposures is at the North and South Poles and along the Equator. Going to Antarctica or Quito, Equador? I thought not.
The problem is at the focal plane. If the tracking axle of the mount is not pointed at the true celestial pole quite accurately, the image at the focus of the scope will rotate two times or less per day. You want it to not rotate at all.
The altazimuth mount can be tilted way over so the bottom axle at end of tripod points to a celestial pole and it will track but maybe not accurately with that Meade GoTo computer. A wedge between the mount and the tripod would be set at an angle equal to your location's latitude degrees. Then enter 90* north or south into the Meade computer as your location.
Another way is to rest the tripod on an "equatorial platform" that will swing in its bearing plate or runner wheels with a motor to follow the stars. You can make one or buy one for many hundreds.
Another device is a focal plane camera rotator device that is motorized and will compensate for the image rotation in camera due to the alt-azimuth mount. Not cheap! And getting it coordinated with the Meade computer might not be possible. The rotator changes speeds depending on where the tube is pointing in the sky.
Even if you pay a lot more for a heavy duty GoTo equatorial or fork mounting that has a wedge at correct angle for celestial pole and good tracking, it will not be precise enough to give round star images on time exposures. Tracking must be actively monitored. This means a sensitive "electronic eye" to send signals back to the computer running the mount motors. This detector must have a view of the same object that is recorded. Either another scope or telephoto lens, or an accessory to view what the camera sees in the scope, called a pick-off mirror. Also not cheap.
As you see, getting into astrophotos is not an inexpensive hobby. Mounts cost thousands. Cameras with sensitive detectors, ditto. Larger scope size increases not only how much light you get to the camera, but how small a detail you can see clearly with high magnification.
The problem with planets and moon details is size of scope. Your brain will interpret a bit more fine marks on planet and in craters of moon as you view longer. But not with a camera. Moving air will blur images. You must take hundreds of shots, then computer stack and clean up the best ones for a good result. See the website of master Christopher Go for astonishing shots of outer planets. For education on techniques, Tony Hallas has courses on DVD for that.
Sky shots of clusters, gas clouds, and galaxies takes superb equipment, perfect tracking during long exposures of hours through filters with wonderful cameras. See what Jason Ware or Jerry Lodriguss or Robert Gendler does. They use huge scopes under only ideal conditions.
The newest ideas are live video cameras with telescopes. People depend on Rock Mallin to make great ones. They broadcast on Internet sites like Night Skies Network from around the world most good moonless nights. Your Nikon camera might be capable of that when hooked to a computer.
Bottom line is blowing money on the wrong items is what most beginners do. You should join a local astronomy club, get good views and advice. Read reference books and magazines like Sky & Telescope.
Here is a nice beginner imaging scope that is offered at good price, should be like new condition: https://www.astromart.com/classifieds/details.asp?classified_id=965106 Telescopes age very well, and that model was not made very long ago. While it might seem a step down from a computerized motion scope, you are getting more optical tube and a better equatorial (aligned with the celestial pole) mounting. Finding objects in the sky can be done with a smart phone or a laptop with a planetarium program (some are free).
If you must get a new one like that Meade, see this one from Adorama sales--a good source, a good brand, a flexible model at your price limit (maybe tax and shipping makes it higher.) https://www.ebay.com/...2178811836 Also on Amazon.
OPT Corp might match that price if they can order it.
I would stay away from Ebay cheap scopes (mostly junk ripoffs) or even nice looking craigslist personal sales unless you have an expert inspect it.

One limitation see with that scope is the 1-1/4" focuser, 2" would be much better; On that kind of budget you could get some good photos of the Moon and so-so images of the brighter planets. For good shots of galaxies and nebulae, think 10 to 15 times your $500 budget. Prices are coming down, but it is still an expensive endeavor.

An alt-az mount isn't suitable for astrophotography - you'll get field rotation. Astrophotography is a demanding hobby - find a local astronomy club and get first hand advice including what to buy and where to buy it. With your budget a goto mount may not be a good idea as you'll be spending too little on the optics. That said, you need a good mount, too!

Low budget, and astrophotography really don't work well together. Plus astrophotography done well, has an incredibly steep learning curve. Having a telescope system on a good mount that can be polar aligned, tracked, and guided are key. And it's all based on the mount.
The mount needs to be able to hold the weight of the scope, guider, camera, and anything else that's bolted to it by about a factor of 1.5 (if the telescope system weighs in at 10 pounds, the mount should be able to hold 15 pounds). And the less you have to physically touch the system, the better your results will be. So have a computer controlled goto system is the way to go.

You would be better off starting with just your DSLR, and a decent tracking platform, just so you can get the hang of how everything works. Then worry about upgrading later as your skills improve.

The absolute cheapest way to go is to make one yourself. These are called Barndoor trackers (or Scotch mounts). They are not goto, but can off a means to do wide field to modest telephoto imaging. You do need a sturdy tripod, and be able to polar align it. And the motorized versions work better than the manual ones.
https://makezine.com/2015/09/11/star-trackers-for-night-sky-photos/
https://petapixel.com/2013/08/10/buidling-a-diy-barn-door-tracking-mount-for-long-exposure-astrophotography/

For the camera, it's best to have a remote trigger for it. Either with software, or with a timer.
https://www.otelescope.com/store/product/4-backyardnikon-10-premium-edition-otl-byn-p/
http://www.ucoolstore.com/timer-remote-shutter-release-nikon-d3100-d5000-d5100-d7000-replace-mcdc2-p-1506.html

I prefer using software, since the images can be then downloaded directly into a computer. Otherwise, you'll need a large memory card for the camera. It is preferred to shoot in RAW format, since you won't have compression artifacts as you would with something like jpeg.

Also, either get extra batteries, or use a remote power source for it. Cold weather, and long shutter times will quickly drain one battery.

And so much more to learn.
http://www.astropix.com/html/i_astrop/intro.html

To summarise, "low-budget" and "astrophotography" belong in the same sentence in the same way "eskimo" and "sandstorm" do.

Have you tried using your camera with just a tripod. Here is a picture of the Andromeda galaxy taken with a Nikon D3200, 50 mm lens f1.8, at an ISO of 1600. I call it DSL astronomy. I've taken pictures of the International Space Station zipping by, sunspots with a solar filter, the Pleiades, etc.

No telescope. Instead get an equatorial mount - a good one - and use your camera lenses. When mounted to a camera, all a 'telescope' does is be a long focal length lens.