the 3850 is a really nice card, but from what i've heard the 3870 is a lot better. also the 3850 is only around 180-220 depending on where and when you bought it/plan on buying it.
3870 = $219 unless the seller has bumped the price (ala NewEgg). AMD has said it will be dropping the price $20 for the Christmas rush... would be nice if they did.
Almost everyplace has bumped up the prices of the 3870. Shame really since for its MSRP it is a great card, but at $350 the cost to benefit ration is significantly lower.