Custom sticker place recommendations and best cheap but keepsake worthy handouts for players?

We're looking to hand out "I escaped!" stickers to our escapees as a memento that they can take home, but yikes is that more expensive than we thought it would be. Can any owners recommend any good cheap but not terrible sticker places? Part of the cost is that we want a sticker that's specific to each room.

But also, are there any other cheap mementos that we could be handing out to our players that you've tried and had success with? We do want players to get a little prize for escaping just because that's a fun thing to have but we're also looking at this in terms of if our players have a keepsake in their home, they'll be reminded of their time here and hopefully also consider coming back