I just bought a used 3,1 with dual quad core 2.8s for $450. It has 12 GB of ram and a regular HDD. The video card is an 8800 and it's running Yosemite. I've been reading about upgrading and see that it doesn't make economic sense to go very far. I'm new to Macs and would like to use this for running FCPX only. I'll use other computers to surf the internet, since it might run better not connected to mail servers, etc It appears these upgrades make sense: -A fresh install of the OS on an SSD -Upgrade the video card to at least a 5770 although I'm considering the value of a 7950. -A USB 3.0 card The first question is how well would it run Final Cut? The second question is whether this is the biggest bang for the buck for under a grand? For me, the alternative is to sell it, abandon this experiment, and continue using Windows and Sony Vegas. There are just too many exciting new cameras right now to be spending a bunch of money on hardware. I do kind of like tinkering under the hood.