You can have your own shops on Special Sauce (and soon our other 1.10.2 based modded servers). We are running a plugin called CarrotShop and it seems to be working really well for this function.
1st off, how to use the shops as a customer. This works the same way for both Player Shops and the Server Shops.
All transactions are done via right clicking the signs. Signs that say [sell] or [isell] are signs that allow you to sell to the shop. Signs that say [buy] or [ibuy] will allow you to buy from the shop (provided the shop has enough inventory in the case of [buy] signs. ("isell" and "ibuy" are server shop signs whereas "buy" and "sell" are player shop signs).
Now, how to create a shop. There are a few steps involved. 1. Place a chest (be sure your area is protected to prevent players from opening your chests). Double chests do NOT work but you can alternate between regular and trapped chests. 2. Place what you are buying/selling in the chest in the amount you want per transaction (you will stock your chests for players to buy from later). 3. Place a sign (does not have to be on the chest, but near it would be better (for mall shops, it is recommended to put chests behind a wall or something). The top line should say [buy] for players to buy from you or [sell] for them to sell to you. 2nd and 3rd lines can be whatever you want (best to say what and how many you are buying/selling). 4th line should be the price (number only, no $ or other symbols. Also, no decimals, whole numbers only) 4. Hold a piece of redstone in your hand and punch the chest, then punch the sign to link them. 5. If you did everything correctly you should see a message confirming the link and what you are selling/buying. 6. For [buy] chests for players to buy from, after the chest/sign are linked, you can go ahead and stock your chest. 7. That's it, you're all done.