Why did you post the same thing 4 times?
3/4" round steel tubing is about $1.60 per foot. You can get at any local steel shop or metal fabricator if you have any local. Or you could price it at
metalsdepot.com I have been writing up the plans for a replacement rack I am going to build and I figure I need about 40-48 feet of it. It'll cost me about $76 just to by the tubing. Then the work begins. It will be similar to the Calmini rack but extend in the front kind of like the Land rover rack: