<prompt> Human: I collect a few small items like older coins I come across when I receive change. I have a few of these 1909 US pennies and while they arent worth millions, they are easy to collect and their value increases over time. Hopefully when Im close to retirement I can sell any that I have or hand them off to my kids. Anyway, what are other easy-to-collect items in which their value increases over time?  <response>: My Pokemon cards 