I have some that i might be willing to part with for the right price. Before you buy some look around see if there is an old backstop or fence that isnt used anymore. I worked taking apart conduit at a power plant for a month. I took down about 2000 feet of pipe and i could have taken as much as I wanted. The problem was it was really hard to get home so i only got about a 100 feet.
You wont be able to get a rail online premade for a decent price, its all the stuff the resorts use or the people who do rail jams, expensive and nice as hell.