(8) We’re pained by transaction costs… In a personal finance column here, Megan McArdle implored her readers to give up recurring payments like gym memberships and subscriptions to papers and services they don’t use. “Don’t buy stuff you don’t consume” seems like obvious enough advice, but Megan had a great point. We’re drawn to subscriptions and memberships and bundles partially because we seek to avoid transaction costs. We’d rather overpay a little than suffer the psychological pain of pulling out a wallet and watching our money go to each gym season/movie/etc.

(9) … but we’re weird about rebates and warranties. Now that I’ve just told you that consumers try to avoid additional payments, I should add that there are two additional payments we love: rebates and warranties. The first buys the illusion of wealth (“I’m being paid money to spend money!”). The second buys peace of mind (“Now I can own this thing forever without worrying about it!”). Both are basically tricks. “Instead of buying something and getting a rebate,” Poundstone writes, “why not just pay a lower price in the first place?’