I've lived a charmed life when it comes to buying used boats. Although I now own the 2017 Z-18, bough new. My two previous boats were both purchased used, off the web and paid for based on pics and talking with the owners. Both those werre paid for before I ever saw them in person. One was a 18' Javelin the other a 20' Stratos both of which I never examined until they were in my driveway, both seemed liked deals to act qucikly on. They were both about 5 year models old when purchased. I had both those boats (at different times) for more than 4 years.. Never had to do a thing but routine maintenace. Neither of those ever went to a dealer for any kind of service or repair. I'm not advocating doing what I did but- there are plenty of reallly good used boats out there that already have all the issues resolved before you get to them. Both sellers were quite surprised that I didn't require more of there effort and attention. You can certainly understand a lot by knowing someting about the past life of a boat, its apperance, and how the current owner acts....