I didn't mean to endorse building a frame, it could be very tricky for some people and you'll want to keep it light. The quadracer frame is definitely not perfect so don't copy it exactly...

 

If the frame is the ony problem, you should definately buy it. I have an 86 and it has never broke, cracked or anything. It always starts and never lets me down. You can get frames on Ebay for $100. Even if you bought the quad for 300 and spent $700 to get in in great shape, it is still worth it. Most LT250s in my area go for over $1500, and not all are perfect.