With the current lockpick situation being what it is, expensive picks with poor retention rates and poopie drops, maybe lock picks that are specific to a dungeon could be added as drops. For example if your party clears a dungeon, everyone might end up getting a pick a level in addition to the final boss chest. However those picks can only be used for the treasure chests in that dungeon.
IMO that would make the situation a little more tolerable for the players (and fun seeing as picks don't drop that much anyways) but wouldn't ruin the economy because 95% of chest drops are junk and a lot are grapes that don't even help your wisdom title. Likewise you couldn't farm an easy dungeon and take the picks to somewhere that actually has good drops.
How about dungeon specific lockpicks as drops?
Winterclaw