A young friend of mine is a starving film student who recently went back to school to complete a 2-year degree at a community college. He has an aging G5 that I've finally convinced him is obsolete. (Which convincing followed him trying to download some 2+GB 3D rendering software that won't even run on his machine from a torrent on my network, grrr.... Pretty sure he can get this legally from school at no cost - IF he had a computer it will run on.) He did an internship I think in the news dept. at a local TV station a while back, and he was part of a student project that won a local Emmy, but he doesn't have his own equipment (other than the aging G5...) and he's been "out of the loop" for a while. I think he's going to take some classes, and that will give him access to equipment for a while, but to do the kinds of things he wants to do, he really needs to have his own dedicated tools. He's home with his parents for Christmas, and pretty sure he's going to get a good-enough DSLR with decent video features (which he picked out, and I concur on the choice), so that part is dealt-with. I tried to explain to him that any cheap, current PC with a decent video card is going to run circles around his G5. I got him to understand the importance of GPUs now, and made a chart comparing his G5's video card (yes, I know this can be replaced, but probably only with obsolete cards...) with current cards ranging from $50 to $500. Even the $50 card is 50 times faster! I think he got it - finally! He's understood the problem that his G5 is being left-behind software-wise, but he didn't know about the shift to GPUs. He's very resistant to the idea of a PC, but a new Mac Pro is beyond his budget, and I'd thought a used one would be too, but then I looked on eBay. Actually, I looked to show him how little his old G5 is worth - he'd been hoping he might sell it for much more than it's worth (no more than $200.) (I think he got this thing when he was in High School, and he's fairly attached to it, LOL.) But I got to looking at used Mac Pros, looking at the completed listings, and there was one that seemed perfect that went for $415. Quad-core, 2gHz, not sure about video card, 4GB memory. I told him he could expand the memory and get a current Nvidia card pretty cheaply, and that this seemed a practical way to go. There were others around that price, so it seems to me he could get what he needs for under $500, though it might need some inexpensive upgrades. I think that explaining how GPUs are being used today helped him understand that he doesn't need 8 or 16 cores, and doesn't need the fastest processors, because core processors aren't as important as they once were for video production. And, so, now the prospect of an affordable used Mac Pro (as opposed to a costly new one) is attractive. I want to help him home-in on the right used Mac Pro. I'm a software engineer (i devleop mobile apps) and use a Macbook and a Linux system to do my work. When I worked at Sony, everybody got a Mac Pro - uh, except the contractors (I got a Linux box). My only Mac experience is with my Macbook, and I know little about Mac Pros except that basically they are a high-end proprietary Intel workstation board in a nice, rugged case, and they run OSX without having to hack the hardware. Sounds good to me. Any used Mac Pros that sould be avoided? Just too obsolete because of X or Y? I think one that takes only a single chip makes sense to keep the price down, that way it doens't need costly Xeons. And, while I know that not all video software makes use of GPUs, incresingly it does, and so future expansion is likely more practical using new/better/more GPUs rathar than upgrading or adding CPU chips. So, I think number of width of PCI-express slots matters. Anything else to look out for? If possible, I'd like to narrow it down to specific models.