Yup, a sub 300 5850 is acceptable ATM. Should the 470 suddenly drop to 300 or less, then we might get more price-cut loving, but thats doubtful the say the least.
The current card heirarchy is well represented in the price scales. No small shift in pricing will change much.
GTX465 - 280
5850 - 300
GTX470 - 350
5870 - 400
GTX480 - 500
5970 - 700
Unless Nvidia makes a price move first and encroaches their price/perf ratio into ATI territory, ATI will be just happy to stay where it is. If the Fermi Dual GPU card outperforms the 5970 AND is priced close, we might see a price drop from ATI on the 5970 alone (down to $550-600), but I can't imagine that would effect the single GPU pricing.