The D50 is "old", for sure, but it always had a snappy, jazzy, straight out of color rendering, which was very DIFFERENT from the Nikon d-slrs of its era and before. The Nikon D40 dropped the in-body focus motor; the D40x upped the megapixel count a bit; the D60 also lacks the in-body focus motor. So, there are the D50, D40, D40x, and D60 models all available pretty affordably. Buuuuut, if it were a new camera for myself, I would scrape up a bit more money and buy a D3200, which is newer and has a better sensor by far than any of the older cameras. The D40,D40x,and D60 all have the "new Nikon" jazzy, straight-ouit-of-camera color look. The D70 and D70s are two 6-megapixel cameras that have a little bit bigger, and to my eye, a little bit better viewfinder images than the D50, or the D3000-series cameras have. The used D50 and the used D70 and D70s are the most-affordable way to get an in-body focusing motor. The D70 and D70s are two of the VERY BEST NIKONS ever made for full-sunlight fill-flash, at very high shutter speeds, due to the dual, hybrid electronic shutter/mechanical shutter system those used.
Prices on used camera can vary hugely, depending on location, and market, and just what the seller needs to sell for. Occasionally, some fabulous deals pop up. I've seen used Nikon d-slr + 18-55 deals as low as $125 within the last six months at walk-in retail here in the western USA. Not sure what prices are like in your part of the world.