I once found a pair of limey green stretch corduroy pants for $4.50, and they fit, although the waist was a little generous and low for me. I bought them, and just wore a long shirt with them to cover my low-riding. I was thinking the pants would make  a great maternity skirt with that generous waist, so I googled and found this tutorial. I was really happy with the results:

Since I didn’t use a pair of baggy jeans, I had to improvise in the back. I made a little two layer ruffle to fill the gap where the former pant legs came apart. It made a good mid-maternity skirt. I am now far too fat for it. Still, I’m happy to have only two weeks left until my due date!