A used laser at half the price of new is one of the most seductive line items an owner will ever see, and sometimes it's exactly the smart move it appears to be. A properly transferred, manufacturer-supported pre-owned platform can let a growing practice acquire capability without the full capital hit. The problem is that the listings that look most like bargains are frequently gray-market units — devices moving outside authorized channels — where the discount is real and so are the service lockout, the voided support, the consumable authentication, and the slightly uncomfortable conversation with your malpractice carrier. None of those make the listing.
The used-device question, then, isn't "is it cheaper?" It obviously is. It's "what am I actually buying, and will the manufacturer recognize it as something they'll stand behind?"