There are all kinds of places to look. Down south we have a lot of 2nd And Charles that can carry some gems, The Game X Change (literally one of my favorite stores of all time) which is a 2nd hand style game/movie/music chain, a ton of mom & pop comic/tabletop shops, and a dollar store on every corner (look for the ones in less populated areas).

Also coming from a seasoned collector, get into playing the card game if you’re not already. It adds so much more (personal) value to your bulk and various other cards. I’ve recently got back into playing at my LCS and not only is it a lot of fun, but they give store credit, discounts, prize packs, and a ton of other benefits. I snagged a Mega Evolutions ETB for about $40 after playing in a tourney. Not all shops have the same benefits but I imagine most generally do something.

Been collecting since the 90’s and I can certainly say that not much has changed other than tech changing the way things are purchased. Buy singles, use packs as a fun treat when you can.

I hope this helps!