i am looking for a mac desktop that is durable has good heat management and is upgradeable, and not super expensive. I thought about imacs, but I want something that I can easily get into to replace parts. I looked at mac minis too, but they seem to overheat and not last that long. the current mac pro is out of the question and too expensive for me, so this leaves me with pre 2013 mac pros. I would use it for internet, virtual machines, photoshop cs6, a little hd and maybe 4k video editing, and some audio encoding, ripping cds and dvds. I am on a tight budget, cant really go over $500.00, less would be better, and I can gradually upgrade and get components for it. my main concern for this is noise and power consmption, I have read that these really bring up electric bills, and I cannot do this, if they do bring it way up, this could be a deal breaker for this, but they do look durable and powrful. anybody with one of these manage to keep thier bills down?