"the software for audio and video editing on the mac is superior and industry standard used"
That has not quite been true since before mac moved to X86, however many do enjoy mac programs and most are available -- I do not know what they are calling media software here for this course, however Adobe are the king of the prosumer (whatever that might mean) world with their after effects and adobe premier and are available on both apple and windows, Apple's final cut is Apple but rapidly losing fans, avid is the "if sir has to ask" pricing option and windows only and I would be quite surprised if they foisted that on their students for first year and to round it off I guess there is Sony Vegas but I doubt that would be being used.
There is possibly something to be said for standardised/baseline hardware, a known software environment that is less virus/crapware hassled, screens calibrated the same way and apple tending to use slightly higher end hardware (no celerons and "I did not know they made DDR3 that small" stuff here, though you could easily outclass it if you wanted to).
"whats cheap but becoming obsolete"
Not a great plan with macs. Apple's support timeframes for hardware, parts and the OS said parts can run is terrifyingly short at times, though whether it will become obsolete to the point of unsuitability in the 3 years for an undergrad course is a different matter. You could do something but it is not as trivial as with a PC where you just think eh stick a SSD, some RAM and a graphics card in and it will be good as new". Float around
https://www.youtube.com/user/rossmanngroup/videos for some of the repair hassles.
" whats good enough for media editing etc,"
What are you planning to edit? Basic 1080p H264 in less than realtime is doable on quite a bit these days -- my dual core and 4 gigs of RAM pulls that off acceptably. If it has to be 4K HEVC and live mixed/edited in realtime then it gets more fun. If you would spec a normal PC to do it though then you will probably be able to have something for homework.
Were I to sprog and send one to media school (or head down that path myself) then I would probably look more to getting a camera + lens, tripod, monopod, shotgun mic and drawing tablet. However I do know computers and can handle the oddities where again I am back on the "it might well just work" scenario. Avoiding such a thing would almost certainly discount a hackintosh as well (mac are basically PCs these days so you can crowbar OSX onto certain setups, they have to be fairly specific to do well and you risk some fallout so eh).
