Same here on the coat hangers. I've never compared cost of rod versus coat hangers, but for the minimal amount of gas welding I do, coat hangers work great.
My neighbor is a certified welder and he uses coat hangers too. I had a metal hydraulic line for my blade bend in half by a tree on my dozer. I cut it and cleaned up the edges, but had him weld it back together. He used a coat hanger. I don't know the preasure that line handles, but it doesn't leak at all.
Eddie