I want a moderately priced macro lens for a nikon dslr?

The lens can be any other brand but a reliable one (like sigma). I want it to have a small minimum focusing distance (cuz i want to get close to stuff)

The Tokina 100mm f/2.8 macro is probably the best performing lens in it's price range. It won't auto-focus on all Nikon bodies but for macro you really don't need it.

IMHO, the Nikon 40mm Micro lens at $275, focusing at about 6 1/2" is your best buy.
https://www.amazon.com/...B005C50H2Y

The cheapest way to dip your toe into macro photography is to use extension tubes with a 50mm lens.

https://www.amazon.co.uk/...019ZD0PR0/

Even though I have a 100mm macro lens, I still use my 50mm f/1.8 with a 12mm extension tube on a very regular basis.

I'm a 15+ year experienced, published wedding photographer and having a GOOD macro lens in my kit is important for photos of our couples' rings.

I use a Nikkor Micro 55mm 2.8 AIS lens.

B&H sells them for $185 used or $399 new.

https://www.bhphotovideo.com/..._lens.html

Here's why the other suggestions are inferior:

Extension tubes use existing lenses in your kit. They're super cheap but image quality will never be more than average because you're using a lens that was not designed for macro. Any distance measurements or depth of field scales on your lens will be rendered useless. Also, if you use a real macro lens, you can also use this lens as a normal lens. In order to use a normal lens as a macro with the tubes, you have to mount and unmount everything from your camera. With a macro lens, it's just the lens. Use it at close distance or normal/far distance. If you don't already own a "nifty 50", a 50 or 55mm macro can be your nifty 50.

Buying a third party lens (non-Nikon) just so you have a new lens with autofocus (if it works with your particular body) is silly. Third party lenses almost always nose-dive in value when you go to resell. They're cheaper than mainstream brands but they are worthless to resell and sometimes don't perform as well anyway. Best to stick with mainstream brands that are known to work perfectly with your camera and will retain value and perform well. SOME third party equipment can perform as well or better than mainstream brands at a fraction of the price so maybe it's worth researching specific examples of this but for the very low cost of the Nikkor 55/2.8 Micro, I don't think it's worth buying another brand.

Finally, most people just don't need autofocus on a macro lens. Autofocus on a macro lens is stupid unless you are shooting something very tiny that moves so fast that you can't focus on it such as maybe a very fast insect. However, most AF systems aren't going to be that fast either! If you want a macro lens to photograph still objects like flowers and jewelry or most insects, a manual focus lens will do the trick at a lower price and better build quality.

Oh and also, the 40mm Nikon Micro is a G lens, it's not full frame. If you use a crop sensor camera and NEVER plan on moving to full frame, get this lens but if you want to INVEST in a macro lens you'll NEVER have to replace so long as you stick to Nikon DSLR bodies, get the 55/2.8 AIS.

I hope my comments have been useful and you'll be kind enough to choose a best answer!

Happy shooting!

Pay attention to Johnny Martyr's reply; he tells the truth and explains why, too. He has provided the best answer thus far.