That crawler body is still $50 plus shipping. So up to you I guess.
If you want a good body, look for an "unbreakable body". They are a lot tougher, come in various colors, and are pretty bulletproof. All you have to do is apply decals.
Every RCer is different. I have bodies just for shelf queens. Even my SCX24's I have custom painted and modified won't see a lot of harmful driving.
If it were me, I'd just buy an E- Revo body to bash with, and keep your eyes open for the truck body you want. To put much time and money into...
If I were to build one, I'd be looking at a heating element out of a toaster oven, or space heater to heat up the poly sheets. Or I am sure one could easily be made using Rene wire and a power source as well. I looked into making a large scale hot wire cutter a number of years ago, and running...
That's really not a bad price for a hard to find body. Even current ones are close to that price. But if it's a body you plan to bash with, I'd be looking at something more easily replaced, or one of the tougher bashing bodies.