I actually ended up doing this. I bought a top spec iMac refurbished from apple (it was £350 less than the new price) I figure even if it drops another £300 when I sell it (about 30% depreciation from the new price) then I’m still in the same position only I can keep the machine for months rather than weeks. I may even just keep the machine entirely if I can. Good to get confirmation on this way though.