That CPU is not compatible with the Asus board. You'll have to use this type if you want to keep that motherboard:
AMD Athlon 64 2800+, 512KB L2 Cache, 64-bit Processor - OEM
If you want to use that Athlon XP processor, you'll need to downgrade your motherboard so it supports the older Athlon's. Why would you want to limit it to under $200? If you want performance, you have to realize you have to spend a little more. Otherwise, go with a cheap motherboard and processor and don't go with that particular Asus board.
Here's another alternative quoted by someone else:
Originally Posted by erythnul
foxconn motherboard - 44 bucks
celeron d 2.8 plain on over clocking - 90 bucks