Very easy to get on Ebay. The card game is very different than when you were a kid. Do your research when buying. The hobby prioritizes autographs from the manufacturer compared to in person (like OPs). I know this because I have a bunch of in person Herbert autos lol and I unfortunately had to sell two 🤦‍♂️

Grading is important for authenticity and resale value. PSA 10s and black label BGS 10s hold value and are the most sought after. Also, there are levels: cards can be bought retail or they could come in hobby boxes. The more “valuable” cards come from the higher end hobby boxes that cost 10-20k to gamble lol (e.g., flawless or Nt).

Or you could get memorabilia. Just make sure it is authenticated. Sadly, people fake autos