paint over pvc that looks like copper....I've used real copper pipes years and years ago (still do) . I love the patina and all of the available fittings, t's, elbows, couplers, bendable tubing, flanges, caps alone or to attach finial I've made or purchased. I've used copper with brass, with black wrought iron...I imagine it cost more now (I used a heavier pipe because of the span of the window).
DIY: How to Make Industrial Curtain Rods - That Look Like Copper - using pvc pipe, a connector, a flange and copper spray paint, you can create your own rods for very little money - via Our Vintage Home Love
Industrial Pipe Curtain Rod In College, basically used this same idea, except I left the pipe the original color and then bought painters canvas at the home improvement store to use as my curtains. Was a very industrial/rustic look. Outdoor curtain rods?