If you guys don't mind, start a google doc and let me know how much you spend on shipping for the year you don't have Prime. I've always wanted to do it, but I've kept Prime because it makes sense for my situation. Because I don't live anywhere near family, I used to spend $50-$60 around the holidays alone.
The woman I live with and I split it because you can add up to 6 people to your Prime account (little known fact?). For $50 Prime is a steal, but I suspect that even if we combined incomes, it would still make sense because she likes to shop.