I didn't consider it too much yet, but probably between 200,000 and 1,000,000 per player, depending on how many, etc

mostly I play with 4-6 people, sometimes up to 8. I'd be sure to have it so I could have more than just a few of the highest denomination.
It would be a while before I got a custom set (if I do) anyway. Plenty of time to figure it all out.