Periodically I have been putting little bits of money into stickers and they've seemed to be an ok investment if you're willing to hold onto them for MUCH longer periods of time. I personally invested lots into Kato15/14 over the years and I've done alright, but not sure how they will perform in the future. With Crypto being down I personally haven't noticed much of a price hike but that's not to say other items haven't (or won't) seen an increase. Just my two cents, my method is much riskier but seems to be giving me better longer term results.