When pondering whether or not to purchase something, I often do in fact figure (or at least approximate) dollars per enjoyment. I figure the enjoyment is cumulative, so I'm much, much more willing to pay a lot for something that I will use every day than for something that will amuse me a short while and then be over or for something which I will use only rarely.

So yeah, I'd pay a couple hundred for a pair of shoes that I wear every day without thinking twice, because cheap shoes are uncomfortable and wear out quickly, and having comfortable shoes makes my life much better. But if I'm thinking about paying a couple hundred for a toy, I have to think really hard about whether this is something I'll enjoy for a long time or whether the novelty will wear off quickly.