An OM-4t in good to excellent condition will likely run quite a bit more. If $200-300 is your range, go for an OM-4 if you can get one for that money, though you'll probably be more likely to get a very nice OM-2n for that price.Originally Posted by reinis
In either case, for a 50mm try to get either the 1.8 that is marked "made in Japan" on the front ring (NOT just "Japan" or "MC") or a 1.4 with a serial # > about 1,108,000. The 1.8 went through at least 5 versions, and the latter "miJ" incarnations are the best and are quite good. The 1.4 improved as well in later versions.
To give you hope, I once bought an OM-2 with 1.4 and pristine leather case for about $65 including shipping. I treated the body to a CLA (most cameras of this age at least need the light seals replaced.