Just a fun little idea I had... since every pack is already printed, what about designing a "roleplayers accessory" pack of sorts. Maybe fun little things to add to the game that don't alter the balance of the game, but add little fun things for the roleplayers. Within that, you can also include the reprinted cards. (Which would lower the amount of things you'd have to design) Then it would be an entire expansion pack and more cost effective?
One idea I had was a pickpocket deck. In the Pathfinder RPG, I have an old list that whenever people pickpocket someone I make rolls on this table. They might pick something valuable, get some pocket lint, or maybe even a piece of cheese wrapped in a hanky. I'm thinking for game mechanics for the card game, something along the lines of if you have a dexterity of d10 or d12, you get the skill Pickpocket: Dexterity +2. You can use it when you attempt to evade a monster. If you succeed, you can draw a card from the pickpocket deck. Could be something useful, or something just to discard. If you fail, you are caught and have to fight.
Just some odd idea that sprang in my head as I was reading this.