I used to collect cards. Pokemon, Digimon, Yu-Gi-Oh, Duel Masters, baseball, hockey...I had a lot of them. In terms of the ones based on anime, I'd collect them for a while, then get a video game version of it, with the odd booster pack thrown in there (and yes, there is an actual Pokemon TCG video game [
LINK]). Usually I'd collect them, but then my passion for each would fade if:
* A new generation of cards/monsters came out that I wasn't necessarily well-acquainted with or fond of (Digimon)
* The game itself fizzled out in the general public, for whatever reason (Duel Masters)
* The mechanics of the original series or game were either slightly or completely overhauled in such a way that the original lost it's flare (Yu-Gi-Oh GX was okay, 5D's, on the other hand...)
* There were way too many sets of cards to outnumber the representation in the animes (All of them had to violate this to an extent, but Yu-Gi-Oh! was the worst culprit)
Had the same problem as you with digimon, only got the base set for the game.
It's true that Yu-gi-oh had way too many sets, at least pokemon you could tell by which game the set revolved arround.
Although in terms of value you could tell where the user got the card just by looking at the card# to guess its value.