Hey, we’ve got cheap tooth fairies here, too! When Eldest Son was little (he’ll be 15 in a couple of weeks) the tooth fairy brought Kennedy Half Dollars. By the time Youngest Son was losing his, we were up to Eisenhower Dollars. The tooth fairy also left a light trail of multi-colored glitter (fairy dust), at least on nights we were creative. Didn’t happen all the time.
I’d get some of those new Sacajawea dollar coins and use those. And forget this $10 nonsense – good heavens! He’ll be knockin’ his teeth out with a hammer! 
-Melin
Siamese attack puppet – California
Still neglecting and overprotecting my children