Good point.
Let your imagination go. It can be a $1000 if you like !
However, for scoring purposes it is a dollar. I owe Mr Ed an apology. He was spot-on. We are talking about $100 dollars for a max. bet, so feel free to use $, units or just a number will do: w100.

My point about using units though had more to do with avoiding confusion regarding my scoring system in the rules. Simple and avoids a little extra work when typing up a list of results every week. So $ OK as a bet amount but the scoring will look different: $100 win @ $9.80 = for scoring:[w100/980]