I'm considering buying my my first DSLR?

The one after alot of deliberation is the nikon D5200 but given this was released 3 years ago is it a bit too old tech?
I would be buying it new out of the box also for 330 pounds

No, not at all "old tech"

Since it can take years for a person to begin to learn the fundamentals of photography, just about ANY digital SLR will be able to keep up with your learning process.

The two cameras I use professionally, a Nikon D300 and D3 are both over seven years old, so do not worry about the D5200 being "too old"

Enjoy your new camera

A little advice before getting into photography, the body isn't all that important, it's pretty much all in the lens. The D5200 is a fantastic camera, but it depends on the lens to go with it. You need good lenses to produce great photos.

3 years isn't that old, and modern DSLRs are pretty solid machines with few, if any, major issues. A decent photographer could get great shots from a D5200. As a first DSLR, it is as good as any - once you learn how to use it well, of course. It won't do all the work for you.

The D5200 isn't what I'd've chosen, but there's nothing wrong with it.

Just make sure it comes with a lens (these things are generally sold as a kit with the 18-55mm AF-S), as your camera body is a paperweight without one. You'll need at least one SD card too, as DSLRs have no internal storage.

I suggest a D3200 if you don't mind losing the flip out screen and automatic hdr, because it has a negligible difference and you'll save a lot. A good lens is more important than a good body.

The D5200 is an excellent camera. Although Nikon comes out with a new version about every year, there are often not enough new improvements to make it worth the price difference.

A great choice. It is cheap because of its age. But its age doesn't mean its not as good any more. It was always a great camera.