If it's just about collecting, collect whatever you enjoy :) If it's about investing and thus some financial growth expectations, things are different, because you are now speculating which products other people will want to buy from you for more money in the future, leaving you with profit. In the second case, there is a ton of info to go over, too much for one post, but there are some good starting points 1. Watch Youtube (but in the right way) Youtube is a gold mine of info to understand which cards are desired by the market, and helps you get a feel for which cards that are available now, will probably be popular in the future. You can go back in time and look at older sets, and see which cards went up 1000%, and which ones only went up 5%. But you will get a lot of info thrown at you and need to be constantly aware that Youtubers are doing Youtube because they have a goal for themselves, like getting views. To get views, they need to play along with the Youtube algorithm. The algorithm favors videos that make people spend as much time on Youtube so you watch more ads and Youtube makes more money. Videos that do that trigger fear, FOMO, etc in viewers. Don't let this guide your investing decisions, it's just market research, resist the FOMO. Most people don't know what they are talking about and just want to make money on youtube to buy more cards, lol. When it comes to pokemon cards, this is my system. Older, rarer, minter x popularity. Older = the longer ago a card was released, the lower the chances of more supply hitting the market. Less supply drives up prices. Rarer = The amount of cards printed, not to be confused with scarcity, the amount of cards available for purchase at any time. Base set Charizard is not rare, it was printed 100000 times, but it can be scarce as in, no one wants to sell theirs and so not many are for sale at any given moment. Minter = the higher the condition of the card you hold, the better for the value. PSA10 is generally better than PSA9 for value gain.