TZ was my first pin, purchased over 20 years ago. If you're willing to pay for a good one up front, I would say mine has been pretty solid over the years. Try to buy from a known seller, and Pinsiders can advise of how much to just trust vs seeing for yourself. I will say that even if a game seems 100% working when testing in person, things can be missed, marginal, or get broken during shipment. Be prepared to do a bit of work no matter what. Even on a brand new game, straight out of the box, possibly even more in that case.
I agree that Iron Maiden is my best suggestion for a game available new that would play similar to TZ. I love the game, but I would not call it a suitable substitute for TZ, despite the similarities. It's pretty bare as far as gadgets go. Granted, mine is a Pro, but even on the Premium, there's no mini-playfield, nothing to equate to the gumball machine, no powerball. I would say IMDN is far more chaotic.