what happens if you use normal 1 3/4 steel and not DOM for the structure? i'm planning to build a buggy but DOM in Chile is just too expensive  

you can use hot rolled electric welded tubing if DOM is too expensive, but it is not as resiliant to denting as DOM is.  we chose DOM over chromoly due to price and the fact that it doesn't require tig welding.

here is a story about when we picked out the tube.

http://www.4wheeloffroad.com/techarticles/body/131_0602_4x4_buggy_building_tubing/index.html