Card sleeves and storage inserts can easily cost as much as a mid-size board game once you add them up across a collection. Whether that's worth it depends on what problem you're actually trying to solve.
Sleeving cards
Sleeves solve a real problem for games that get shuffled constantly: edge wear, bent corners, and the slightly grimy feel cards get after enough handling. For a game that gets played dozens of times, that's a legitimate reason to sleeve. For a game that comes out once a year, the cards will likely outlive your interest in the game regardless.
The other reason people sleeve: making cards from an expansion indistinguishable from the base game, so opponents can't tell from the card back that you're holding something special. That's a real consideration for competitive deckbuilding games specifically, and mostly irrelevant elsewhere.
Storage inserts
Foam or plastic inserts mostly solve a different problem: setup and teardown speed, and keeping components from rattling around and getting damaged in transit. They matter a lot more for games you bring to a friend's house or a game store regularly, and a lot less for something that lives permanently on a shelf.
A reasonable way to decide
- If a game is a "forever" game you expect to play for years — sleeve it if the cards shuffle often, insert it if it travels often.
- If you're not sure yet whether a game will stick around, hold off. Money spent organizing a game you end up trading away is money you can't get back, while the game itself often retains decent resale value.
- Generic sleeve sizes (standard "Euro" and "American" card sizes cover most games) are usually cheaper than insert solutions and useful across many games, so they're the lower-risk first purchase if you're going to start anywhere.