Flywheel pullers are cheap. There's one that fits almost every two stroke bike out there (125's, 250's, the KDX, and many more). I think I paid a little over $10 to have the dealer order me one through Parts Unlimited.
I made one for my '88 kdx. The ones for my bike were expensive since it is old. I used an arc welder and some scrap steel laying around. I had to buy bolts though.