That is a stupid reason to go with any CPU. Product descriptions will tell you which socket type each motherboard and processor is....
I agree. Unless you're a dumbass, and don't read, you should know what processor can go with what board.
To OP :
If you're good at following directions, you could build a fairly nice system, for around $500. I just ordered parts to completely overhaul my computer changing everything but the optical drives, case, OS, and monitor for $435.
AMD 7750 Kuma Black Edition (2.7Ghz Dual Core)
ECS A780GM (Not the greatest board out, but well worth the $70)
Wintec AMPX DDR2-1066 (Seems to do the price justice, but we'll see after a bit of overclocking.)
PowerColor ATI 4830 (Great card for lower resolution monitors, and for $75 after mail in rebate, it's a GREAT card.)
250GB Western Digital Hard drive (Always a good brand, no complaints.)
Sunbeam Core Contact Freezer Heatsink (Suggested by many friends, suppose to keep temps down really well. Said to let you overclock quite a bit.)
Apevia 680W PSU (Decent reviews, only bad thing I can think of as of yet is that it's not a modular power supply.)