Just curious, what is "pricey" at your end for a 6x6 especially? While what I have recently paid here in EU for a Rolleivision 66AV with Xenotar lens isn't cheap per se, it is far lower then most current prices for same configuration, so there are still deals on high quality projectors. But again, what is a deal for one, it may not be for another. Full manual shifting tray arrangements has advantage of basically just bulb and ventilation going bad, plus lens quality. So in your case, if you're getting for under $100 it might be worth it. But I would advise to check out what the lens is and what bulb is used. If bulb is no longer available, you already have an expanse to deal with. If lens is plain pizza variety? Is it worth any money for so so projection?
So what projector is it and what price are you considering for it? It will help with more targeted answers.