That works. Though now card price doesn’t actually reflect a character’s implied probability of surviving. Eg buying a card at $40 is a confident move if there’s a chance of two survivors, and always loses money if there’s 3.
Instead it’d be $100*p(surviving|1 survivor) + $50*p(surviving|2 survivors) + $33*p(surviving|3 survivors)… which makes it a lot harder to think about whether to buy or sell. Could make things more interesting though.