I told my son the truth about the tooth fairy. So now he just hands over the tooth (when he feels it's ready to come out) and we go to the store to get a Power Ranger toy that he has been wanting. My son doesn't like blood or anyone touching his mouth. So it's a big step for him to have a tooth come out.
With my oldest, the tooth fairy always left two dollar bills. If you ask your bank, you should be able to get some. Since they aren't normally used, my son felt VERY special to have one. It also helped him save the money. He didn't want to spend the bill as not everyone has a two dollar bill!

We made a special tooth fairy mail box next to the bed! My daughter is a light sleeper and this solved the problem. For gifts she gets cool toothbrushes, cases for toiletries, books, etc....I don't believe in the money for teeth idea. My husband wants to leave $5! I think not!

The book "the night before the tooth fairy" may help.

my son with Asperger's always let his tooth fall out on his own, he wouldn't pull them; but we left coins from other countries as my husband travelsa lot (& so does the tooth fairy)

If he is into money the yeah go with that. If he likes matchboxes the you can always do a little car but make sure you have a supply on hand because you never know when a tooth will fall out. Sucks when they loss a tooth and you don't have anything and have to run out after they go to bed or come up with something fast.