1. You pay a hefty startup fee to create your shop. 2. You can open and close your shop. 3. There's a operation fee that you pay every hour that the shop is opened. 3a. You automatically pay the operation fee even if you're offline. 3b. The shop automatically closes when you have to pay the operation fee, but you can't afford it.4. When you reopen your shop, you pay the operation fee for that hour. 5. The bigger your shop (the more items or blocks you have for sale), the bigger your operation fee (a lot bigger so specialty shops thrive) or have a upgradable limit of items or block you can sell in your shop (upgrading the limit ideally cost a lot) 6. The way you see or enter player shops could be similar to /is warps. 7. You can't enter a shop that's closed. 7a. If a shop is closed, and you're in the shop, you're automatically kicked out.8. You can't sell items or blocks in your shop for free (this could destroy the economy, minimum price could be based on the shop keeper island level or at least half of what an item or block cost in /shop). 9. Maybe you can receive notifications of transactions at your shop when you're online or a recent history \ log of those transactions. 10. I am out of good ideas (this is my last edit), but I envision player-created shops as a free market, taking the economy in the server to the next level. I believe that a lot of the ideas on this list can be accomplished by tweaking the code or changing the settings of an existing shop plugin.