New up! vs. Golf etc. used (the economics thread)

Hello guys, the topic in the thread “Which up would you order?” is now quite drifted off. I’m going to open a new thread here, as a follow-up to this post: click! At this point we can leave out why the up!, the Citigo or the Mii as a new car compared to a used car of larger class (e.g. Golf VI) is more economical, that is: Why can I drive the up! over runtime/stop time cheaper than the x-year-old used ones? ( Or the opposite.