I agree you have to have a rudimentary sense of the value of points to figure out which credit card to use, or whether an Amex transfer bonus makes transferring worthwhile. Etc.

I also agree there is a fair amount of irrational behavior out there, like using a southwest card to earn 1 RR point worth 1.7 cents instead of 2 percent cash back (barring working towards a companion pass or something). Then agan, it's easy to get 2.66 cents toward plane tickets for $1 of spend using a citibank thank you card, but stll people use 2 percent cash back cards and spend cash on plane tickets (or, hopefully, use their Amex gold cards which reduces the problem slightly). So go figure.

All that said, I still get confused about valuing a mile when I can't otherwise afford to purchase the ticket or purchase the miles. I want to fly 4 people to Europe in C. Even if I could get unlimited miles for 2.1 cents, I don't have $8400 to spend. How do I value 400k miles? It feels to me like they are worth more than $8400 in terms of allowing me to do things I otherwise couldn't. But maybe that is irrational.