Goodluck getting one in that price? Infact if you can, get me a fully working RXZ 135 engine with carb and CDI in that price alone, I'll be glad to get it off from you. as for your bike, I can offer you 4K cash right now. since i know about these bikes quiet a lot as well, if not more.
and here comes your knowledge quiz.
What size is the main jet on an RXZ 135?
What is the part number of the Connecting Rod used on a RXZ 135 or a 115
What is the Length of the connecting rod used on a RX115, RXZ 135?