We just bought two Dell servers for a total of $500. One had 2 Xeon CPUs with 8 GB of ram and the other had 2 Xeon CPUs with 4 GB of ram. These came without hard drives though. They were previously owned by a bank and when the warranty ran out they got rid of them. The bank places a premium of reliability and service. Apparently they had a contract that said they could get them fixed in 4 hours or something like that. When the computers were out of warranty they wanted to get rid of them so we picked them up for cheap. They work, we must only buy hard drives. Obviously the bank did not let those go.
These computers are now the most power computers we have. They sound like jet engines when running and make a lot of noise but they will do just fine in our server room.
The point is that if your company needs some power computers you should check with the banks.
Note, while these are extremely powerful computers they are noisy and not really suitable for home use unless you are deaf.