I have designed a trailer for my operation starting next spring. I plan to purchase the material and build it from scratch using my dad's help (and his welder). I feel this will be the less expensive route. We have built a few small utility trailers together in the past and working on one right now just to sell. In researching the trailer Manf.s in my local area, I have found they all use angle. Some larger manf. (Wells Cargo) uses "c" iron. The most expensive trailer manf.s use sq tubular. I am trying to balance cost with quality and longevity. What are the advantages of building vs buying and angle vs tubular.