Bukkit

Would it be possible to have the chest shop drop experience when a player sells items?  Would be a great incentive to use the shops

That's an interesting idea although it should probably done by a separate addon plugin (ChestShop provides events for listening on transactions) as most people probably don't need such a feature. Also what needs to be considered is that players could create shops just to generate XP, there would need to be some sort of system that stops that like only giving XP from the admin shop/specific players.