like fox said, you can get some good deals. i rebuilt my 99 cr250 for 430 bucks. it came with a hot rods crank, bearings, seals, wiseco piston and rings. it came with an athena gasket kit but people where having issues with not getting all the proper gaskets. it all came as a kit so when i got mine i had to many gaskets. so i ordered an oem honda gasket kit. i read reviews and i was unsure of the quality of athena and i didnt want to take a chance. get a good manual and pay close attention. read the chapter first then go ahead and do it. i know for my bike i found a good instructional video for rebuilding my bike, i found it on youtube. you still need a manual though. get the proper tools for splitting the cases. dont hack them with a screwdriver. bag every screw and lable them. put all the bags and parts in a box so you dont loose them. take picture of anything complex. also, make sure you clean out the reeds and assembly. make sure theres no sand hidding in there or anywhere else. go slow.
-mike.
-mike.