So one patient every two years needs one dose of an antivenom. Charge them for the dose of antivenom. Then add up the unused stock as administrative cost and spread that over all emergency care. Simple and effective.

Do the same sort of thing for all other short-half-life things that you must keep on hand.

It doesn’t have to be hard. I get that it is complicated right now, but let’s focus on the idea that simplifying it would help everyone.