The way graphics cards generally work for nvida cards is that if the 1st number is higher, its a better card. 650 > 250. Also, when it comes to nvidia, GTX is usually better than GTS.
And for future reference, the second number also determines the sub-class of the card. In this case both are the same though. However, the 650 is still much better than the 250.
The GTS 250 never cost $200 anyways. I got one years ago when it had more recently come out for like $100 after rebates. Getting a GTX 650 for $100 makes sense.