my thought exactly Simon - and how easy would it be to buy replacemnt parts for those items in need of fittling?
I'd feel like buying a seven year old Aero, with less than 150 miles on the clock, would be like an exercise in frustration, trying to resolve all the issues created by lack of use (let alone the standard ones that present themselves).
I'd take a cherished, well used and cared for vehicle over one that has barely turned a wheel. In my experience, mechanical items don't fare well with lack of use.
Add to that the conundrum of whether someone would want to use it after paying a premium for low mileage example?
I used to joke that microswitches, A/C issues and a new sump were the bare minimum annual additions to the standard servicing on a well cared for, but regularly used, Aeromax. I can't imagine what the bill for a low miles car would look like when taken to MMC.