The best deal on beach wheels??? No such thing! Your best bet is to find someone who inherited them from a dead uncle or something, and doesn't know what the heck they're for! Even used ones price out close to new. If you find out let me know. I have a set of the hard beach wheels (cat trax) that I'd be willing to trade for a set of soft ones or a 30 to 40 foot yacht (or a house in the Keys).
Anyway, good luck!