I do golden dollars. As in 1 per tooth.
The tooth fairy was caught offguard at one point, though... so I had to dig in my travel stash, and he got some euros (metal) once or twice, and yen once. He SCORED in the exchange rate there (our house must have been the first house after the kids in the EU or Japan ;)... but in general, it's $1
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My baby brother just lost his first "hockey" tooth. My mum and his wife put their heads together and put a new mouth guard and a filled out check (for the cost of the dental work) to "Baby Brother's Wife's Shopping Fund" under his pillow. So now HE has to pay (double, to the dentist, and his wife) whenever he's stupid enough to play without his mouthguard.
"But it was "just" a pickup game!" is now met with "JUST Jimmy Choos! That's all I'm saying. Fork it over."