Whether you're a cardist or a card magician, you go through a decent number of decks of cards. There comes a point when a deck is no longer usable in card magic, and the same can be said for cardistry. They're both different times, mind you, but the times do exist.
As a person who primarily practices card magic, I can kill a deck in a single day. I say this, but I tend to use the same deck for a whole week before swapping in a new one. Why? To get used to different levels of deck-fluidity, of course. I'm just kidding, it's because I'm lazy =P
By the end of day 2, it's harder to fan the deck. By the end of the week, even spreading the deck between my hands results in clumps. Ugh.
However, the last day or two, the deck is really good for practicing cardistry moves where packet cuts are required. Since the cards clump together and are far less slipper compared to a new deck, I only drop the deck about 80% of the time!
After the week's up though, what to do... what to do? Well, I throw it away. Plain and simple.
I mentioned this to a few friends on Instagram and they flipped. They aren't necessarily deck collectors, but they hold onto their poop decks too. Why? No idea. Maybe because these things cost between $10 - $20? The way I see it though is that it's like any other consumable good. Once consumed, it's gone. A coffee from Starbucks easily runs $5. Back in my heyday, I'd have one almost every day. Did I keep the cup after I drank it? Nope. So, why keep the deck after it's no longer usable?
I do have two exceptions to this. One is for photogenic decks. I have my first 1ST V2 deck still and it is beyond dead. However, it still looks great. Whenever I want to use a V2 in a photo or video, that's the deck I grab so that I don't overwork one of the others in my limited stock. The other exception is for decks that aren't on thin crush stock -- like Bicycle Standards. With those, I practice gimmick making (i.e., card splitting and flap cards). I've tried splitting thin crush cards and, well, I'm not doing that again =P
So, what do you do with your old decks?