Can you weld or have you ever done any brazing? You could build your own for probably $50 worth of material. The guy that does Chips chassis work is really good, the most realistic tubework I've seen. The quality is about to the same standards as the Boyer stuff, but to me the Beckworks stuff looks more scale realistic with the 1:1 stuff. Some of Boyers stuff is incredibly intricate and has more details than the Beckworks stuff, but because its kinda far out sometimes it doesn't look as realistic to me. Anyway, Boyer is on the top of his game and Beckworks is right there with him.
There's A LOT of hours in building a tube chassis thats modeled after a 1:1 chassis. He has to look at the photos and build everything to scale. So what that means is that if he was freehanding a chassis, the best thing to do might be to do a cross member that takes an hour. But if the 1:1 doesn't have a crossmember like that, then you have to match it up exactly, so there might be 4 hours extra just to match it up correctly. That's why they cost as much as they do.
However, there will be some production models coming out with tube chassis's for the MRC, that you'll probably be able to buy for around $100. Hopefully places like Sinistir and Death Metal Garage will soon be releasing 1/18 scale tube chassis.
Also, I may be producing a chassis soon for the cliff climber, and maybe the MRC as well. I'm getting ready to start a cliff climber because of the motor over axle setup, and I can use two cobalt motors. With the right chassis, I think it will be a hell of a mini comp rig for the 1.9 class next year.