Real Ultrasuede is not at all cheap, but I have some of it in my stash. I get it at thrift stores and church sales, it is mainly made into jackets for more affluent folks. Since it is usually about 50 dollars a yard last time I checked (Okay, some years ago, the price shocked me out of the store) the cheapie jackets I grab and cut into pieces and then stick them in my stash till needed.
I presume you need a lot of it, so can't help you much there. Couldn't you use some other color or shade of it? Or some other fabric?