Hello everyone! So I was browsing eBay and found that the old Mac Pros (the ones before the cylindrical Mac Pro) go for about $300-$500 a piece. And to my surprise, the hardware seems pretty good! I've actually been thinking about building a Windows desktop, and was wondering if the Mac Pro would be a good basis to start with. I want to do some gaming and photo/video editing as well, so is it possible for me to upgrade the GPU that is inside? I've read that they come with nVidia GPUs', but do they use PCIE? Also, is the CPU, RAM and HDD upgradeable? I mostly want to do this because not only is the desktop cheap, but it comes with some decent specs, and most importantly, the great design! I'm sorry if I sound like an idiot (I know I do!), I'm extremely unfamiliar with Apple products. Thank you all!