My motherboard, RAM, and processors were all used. I wasn't concerned too much about the RAM or processors, but I've seen a lot of posts about people getting bent CPU pins on used motherboards. Luckily, everything was working for me when I got it.

I was initially considering a new Xeon E3 system, because I wanted to have ECC memory, but the price on these used components had a significantly better price/performance ratio. Whenever I decide to update to a new system, I'll be looking at something like this again before I consider something new.