Normally temporary servers doesn't utilize much CPU if you have good CPU and high HD I/O. ET, COD and quake3 series game are not much CPU extensive games compare to new ones. They where designed to run on 1Ghz CPU's and now we have 3Ghz+ quad core with HT CPU's for server.
At the same time he can also promote his main game server business by providing free test servers. I believe it's good idea.
Good luck Poseidon!