it seems impossible to find a dual core chip for under $250-300. Are these chips basically discontinued? Do I need to go the E-bay route at this point?
You can find a few dual-core socket 939 CPUs on eBay. There is at least
one FX60 plus a few 4200 and 4400 chips on there today. Prices are
very high compared with equivalent AM2/AM2+ devices. It would be
very difficult to justify spending $200-300 on an old CPU when
you could get a faster CPU complete with a new mainboard and
RAM for the same price.