I've seen them too; I think the set sells for $12.99 at my Price Chopper? I've also seen a smaller set, with the two smaller-sized ponies, for I think $7.99?
They must come in different colors; I have one that's the same size as the blue one pictured in this set, but mine's white. I think they're really cute, personally, but not at all worth what they're charging.
The flocking peels off very very easily, and they're very thin plastic. The eyes are some sort of sticker, and their hair is basically glued on. I don't think you could even use one as a custom base; re-rooting them would probably crush their poor fakie skulls.