I built a backdrop frame out of PVC pipe myself not all that long ago. I suspect it's a rite of passage for budget-conscious photographers because I keep stumbling across other people's writings about how they built their frames.
For example, here's Jeff Geerling's page about his frame. I like the feet he built, and I like his solution for wrinkle-free material. When I rebuild my frame, I will cheerfully use those two design elements.
Why don't I just go buy some Autopoles and be done with it? I'm saving up my money for lighting gear and lenses. Duh.