I was trying to post this at work but it wouldn't go through for some reason. Anyway...
Looks like its the same board used in an eMachines system. According to the spec list, the board is even quad-core compatible, but to keep the cost down, you could go with something like this:
http://www.newegg.com/Product/Product.a ... 6819116076While it's a Pentium versus a Core 2, it should be enough since the clock speed is high. The lowest priced Core 2 is around $115 as far as what Newegg has in stock.
http://www.newegg.com/Product/Product.a ... 6819115056The compatible CPU list can be found
here. Personally, I wouldn't go any lower than a 2.0GHz, and at minimum, I'd use a Pentium Dual-Core, with a Core 2 being preferable.
As for a cheap video card, CUDA offloading MIGHT be enough to make up for the CPU bottleneck, but I'd say the CPU investment is going to be more useful in the long run. However, while not amazingly powerful, this would allow you to use CoreAVC's CUDA offloading, and it's only 18 bucks after the rebate.
http://www.newegg.com/Product/Product.a ... 6814127412Between the video card and the CPU, especially with that rebate, you could come in under $100, add CUDA, and have a pretty decent boost in performance.
OZC is not an expert, he just plays one on TV......wait, I take that back. I do this stuff for a living.