Amazon can have some great prices, and they are good. But, I've been shopping at Newegg since 2004ish and I've spent quite a large amount of money there. I've NEVER had a problem with them. Fast shipping, good prices. If you're in the US and arn't going to pick up the items your self at Microcenter or Fry's, I would recommend Newegg over anything. Amazon can get some crazy good deals, however.
But with Newegg. the GTS250 is cheaper (and its a great version).