Hey les, I would reccomend going on to ebay, they have some cheap ones that I was looking at a while ago, I wouldn't reccomned getting the expensive ones unless you were planning on competing they really are too expensive!! But ebay really does have a good selection(at least right now), you also may want to go to any local dance studios and look for the older tapes, they are in every way just as good, but they cut prices on old stuff. I hope it helps.
-Dan