Here in Germany you can get them for as little as 120 €, a HD 5750 starts at 99 € and a 5750 at 125 € - all with one Gig, all from reputable shops. So, Nvidia still tries to capitalize from brand recognition and feature set. Performance alone would dictate somwhere between 105 and 110 € - but the card's listet on it's first day, prices may change soon.That's the problem though, at least in the US. Reference GTS 450 is priced the same as reference 5770 but is generally slower. OC'd GTS 450 has one card at 10 USD higher and others even higher than that. At that point you'd be better off just going for a GTX 460 at 170 USD. Taking prices from the Anandtech article since I don't see GTS 450 for sale yet.
1950XTX 380M transistors
HD4350 242M transistors
HD5670 627M transistors
Right, I remembered wrong. But: the point is, that it's worthless to compare older architectures with less features with modern cards - on any side.