Another way of saying this is just that you need to be aware of the current market price at which you are purchasing utilons, and you need to justify budget decisions by comparing the utility of the thing to be purchased (NASA rockets, food aid, Starbucks coffee) to the going rate.

If an opportunity comes up to purchase utilons at a cost substantially below the going rate, you should happily make the purchase, and balance the budget by dropping other purchases that are more expensive relative to the amount of utility they provide.

This scheme is much much efficient from a computational standpoint. The "food aid" vs "NASA rockets" model of budget analysis, you need to make N-squared comparisons, where N is the number of budget items. By keeping track of the utilon-dollar exchange rate you only need to make about N utility calculations.

Regarding cryonics, the problem is not that we're irrational regarding how we spend our money. The problem is that it's enormously difficult to evaluate the expected utility of cryonics.