Honestly, it really doesn't matter how bulldozer will preform so if you can wait for Ivy-bridge and Bulldozer to release then get sandy bridge anyway, as its very likely they will lower in price.
That's what I mean about there always being something better just around the corner. If not Sandy Bridge, it's Bulldozer. If not Bullzoder, it's Ivy Bridge. If not Ivy Bridge, it'll be something else 18 months from now. Maybe the price of solid state hard drives finally becomes reasonable, who knows. Point is, there's usually something cool coming in not too long, and that usually also makes the previous-gen stuff cheaper. LGA775 seems to be the one exception to that; it's always stayed about as expensive as ever. For what reason, I have no idea.