No idea, but seeing as they can be bought for coins, I don't see the point in buying them with real money. however, for $5, you had better get every power-up forever and ever.
That is my biggest gripe with these Freemium games: the IAPs are exorbitant. Most non-Freemium games of this caliber retail for $2.99 to $4.99. But here you download this guy for free, boot up the IAP menu and they're charging $5-$100. For $5 it should unlock everything but it doesn't. Absurd.