A new rig would only be about $520. You can pull the board, cpu and memory out of your old rig and install new. keep the case, power supply and any other peripherals you need. You do not need to replace the entire pc for $2000.Then recover some of your costs by re-selling the the older CPU and DDR3 memory, you can even get a few bucks for a DOA 2011 board
I completely agree with you, especially, when trying to save some cost. The RAM and the CPU are still very useful. He should scavenge the necessary parts he needs from the old computer and gets new motherboard that would work well with them at a reasonable price.