Replying to Cost to build a rail?

So I would like to build a rail for my final project for fabrication class (Welding). So I was wondering if anyone here worked in the industry or anyone just happens to get metal prices for fun..... How much would it cost for 18 feet of 4" x 2" steel and 12 feet of 2" round tubing? I know prices are fluctuating alot right now, and they are alot higher then normal but I have to finish it this semester... which is like a week and a half.. Also I'm not sure what the steel needed to construct the rail is called.. Help would be appreciated!!!!