I purchased a "gently used" Z400 last year and I love it. That being said if you do plan on buying one, get detaled service history. Z400's are notorious for cheap OEM valves (dont believe me google Z400 wont start) Shortly after I bought it (one ride) it would not start when trying to unload off the truck. After some reasearch and a top end rebuild the thing is a beast! If buying used and the previous owner has had to adjust the valves, I would plan on replacing them soon. I put kibblewhite valves in mine. Parts for the rebuild ran about 5-600 but that included new cam chain, piston and rings as well as the valves. Love the quad but watch out if a used one is hard starting, it will need valves. Cant go wrong with a Honda, but my Z is faster than Max's 400EX