I found a 2011 ddo a couple of years ago. At the time there were only 30 or so found and it was valued at around $50. I slabbed it but since then more have been found and I've seen them on eBay for a few dollars. The opposite can happen as well. The 1997 ear and the 1982 ddr come to mind. At first they weren't valued that high but since only a couple have been found since they are worth more than early estimates suggested.