I've stated that the Apple Mac Pro isn't the greatest in terms of price versus performance. They are performance powerhouses but they are also very expensive. I don't recommend them to normal users because normal users would not need the power they have. These computers are meant for graphics professionals and people working in the film industry. They are overkill for someone who just wants to check their email, write a document, or browse the internet. 

That being said, we've still found some good deals on them. It's hard to find a good deal on a used Apple Mac because they typically hold their resale value pretty well, in comparison to other PC brands. 

As I stated on the iMac and Mac Mini pages, confirm that you are purchasing an Intel-based Mac Pro. Do not buy a G4 or G5 version of the system. These are older systems and modern applications no longer support these CPUs.