I have been pricing steel for my DIY More Beer gravity system. I only need three 20' pieces (not even that, but the local steel supply store will only sell it to me in lenths of 20').
1 1/2" X 20' angle iron= $22.82
2" X 1" X 20' square tubing=$34.21 (ouch)
3/4" X 20' square tubing=$9.00...