Using your money analogy, what I’m saying above is that if you expect the item to cost $20, you will go to the shop with only $20 or $25 in your wallet. So you won’t buy the item if it costs $100.
This theory is compatible with willpower being expendable—obviously, you can’t carry more cash in your wallet than the total amount you own.
So it is a more detailed model, in which you can be short of money in two ways: you can’t afford this at all, or you didn’t think to have that much cash on you when you left the house.
Using your money analogy, what I’m saying above is that if you expect the item to cost $20, you will go to the shop with only $20 or $25 in your wallet. So you won’t buy the item if it costs $100.
This theory is compatible with willpower being expendable—obviously, you can’t carry more cash in your wallet than the total amount you own.
So it is a more detailed model, in which you can be short of money in two ways: you can’t afford this at all, or you didn’t think to have that much cash on you when you left the house.