It's 60cc's, not 50. $400 is a good price if it's in really good shape. The front fender is long discontinued and the centerpiece to any good Zinger IMHO.
Call me crazy, I am wired slightly different, but I'm not sure how I feel about you posting an ad asking us what something is worth just so you can make money from a fellow enthusiast. I know people do it all the time, but they usually keep the details under their hat. Maybe it's just me, I don't mean to sound like a dick.
85 Tri-Zinger 60
85 ATC250SX
86 ATC250SX
87 ATC250SX
02 XR650L conversion
84 ATC 480R