Mr. B and I have a real disconnect on the idea of "value" I guess.
I think this statement is exactly right (this is, in fact, about value-- not about stuff). I am with Mr. B. on this.
The claim is that with Boomerangs little scheme she would be getting $120 worth of shoes for $41. The problem is the claim that the are worth $120. How do you calculate "worth"?
Obviously the original calculation is based on the normal full price-- if they cost $120 they must be worth $120. There are a couple of problems with this logic.
1. Spending $120 now (or whatever part of this $120 you won't use right away) for something you will not use for two years means that there won't be $120 to use for other things. You could avoid crazy interest rate by paying down credit card debt, or buy stuff you really need now, or even put into the stock market.
Your are basically losing the use of this money for a long period of time.
2. There is risk that you will lose your "investment". What happens in two years when your son refuses to wear shoes that are out of style. When your kid feels a strong need to have Brand Y, you either have to force him to wear Brand X (no matter what his friends think) or you are going to be spending more money.
3. What happens when Brand X has a sale in six month that would have given you an even better deal? This obviously lowers the value of your current deal.
Your plan paying todays prices now for future shoes is an fairly risky proposition.