On the other hand, it's supposed to be an amount of money that is enough to subsist on. If there's a relatively predictable perception of "subsist" in terms of

On the other hand, it's supposed to be an amount of money that is enough to subsist on. If there's a relatively predictable perception of "subsist" in terms of proportional allocation to categories of goods in a basket, prices for goods in this basket might start to track their respective allocations. On another note, who says the rational thing to do with a windfall is to go blow it on something just because you can?