That provides a use. No, that idea, though good, would be more appropriate for Summoning. Something like a dragon or crow, that's known for hording things of a gold/shiny nature. Well I'm not against cash shops having a unique use outside of equipment bonuses or acting as raw materials. It's when the cash shops directly interferes with the economy by disrupting the traditional means of these, through our usual raw materials/armors/potions/etc that the cash shop has a negative impact on the game. The fear is that cash shop items would cause existing items to become obsolete, thus affecting the economy harshly, but this wouldn't be the case if an item held a completely unique ability such as drop retrieval. Although I do agree that adding it in with usual game content, such as an update to summoning, would be more appropriate.