If you plan on playing out a lot, keep it as backup. It’s small enough to take with you as a spare controller to your gigs. Something happens to the SX, you’ve got a backup. Never assume because it says Pioneer (or Denon, Numark, Reloop, whatever) that it can’t break down. Also rest assured that Murphy does not think any kinder of DJs than he does of normal folks. His laws apply. Therefore, if something can break, it will and and the worst possible time.
I still carry around enough gear (except for a full PA, but all three my speakers are active) to get me through any gig, regardless of what major components break down.
For what I know of the VMS2, the secondhand market isn’t too hot, with it being not all that expensive as a new product, so I doubt it would make you lots of money and/or devaluate a lot if you hang on to it a bit longer.
Greetinx.