Well I'm actually pretty sure they are based on yen like bells in Animal Crossing. This would make sense since 100 yen is roughly equivalent to one dollar. That's mean about 10,000 dollar for a bike…
…That's kinda bullshit too.

Come on, man
Can't you spot me that last pokedollar?
I'll go beat up a 6 year old's pet and pay you back, I swear