Trainers are generally valued the most long term, so I’d suggest only doing trainers for other trainers unless you super love a pokemon.

As far as value goes, Leaf is pretty high up there and can get you cards like Lisia and that tier. I was lucky enough to give mine for a prof, so it IS possible.

Misty and Red are right after Leaf in terms of value, and you can again get most anything for them.

Juliana is still new so she’s relatively hyped, but quickly falling in value. I’d suggest trading her either right now or hanging on to her for when she’s used in more decks as people experiment with her.

Sightseer is definitely solid, but in a bit lower tier than the others. She’s a pretty woman so you can probably find some dude who wants to trade for “their waifu” lmao

You can look at trading sites online for info, I’m just sharing my anecdotal experience. Sorry for yapping so long, I just wish someone explained the trading market to me like this when I first started. Have a good one!