Depends how much time you want to spend on it, or how much money you want to get back. My suggestion for maximum money with minimum effort and time is as follows. Take out all the holos and rare cards and sell those on their own. Here it may be worthwhile to go into a card shop or comic book shop and see what they’ll offer, it could be nothing, it could be more, really depends on the card and if your area has kids still playing the game. While you’re in the shop, look on the wall to see if they have a Pokemon card league, cause you could go and sell your cards off there I imagine (as well as potentially making more money by selling your rares directly to them rather than letting the store take that profit). Once the holos and rares are gone, you can sell the commons/uncommons as batch lots to individual people to get rid of them for whatever change you can get, as they really are worth very little at all. Throw whatever’s left on Craigslist/eBay as a last resort to get them gone.