First off I’d like to say your System looks the most promising so far. I like it! I don’t really find it necessary to provide better graphics (others may think different), as long as it’s easy and flexible to edit for the Customer (maybe you could share some insight how to change the background image or Inventory size?). It’s hard to tell a fair price, especially since the features are not final and the marketplace is still in a very early stage. However for something like a Inventory System (potentially high demand) I’d rather go for a low price and sell more copies.
Well then…
- optional weight system for inventory and containers (as it correlates with other features I suggest, and after all I don’t think it bloats the system more than it adds)
- possibility to limit the amount of items a container/inventory may hold
- possibility to limit the item(class) a inventory(container) or slot? can hold (actually similar to how your equipment works)
- possibility for specific slots to pass information to the item it currently holds (e.g. telling the item it’s burning, it’s being powered, refilled etc.)
- possibility to add nAmount of independent quickslots (should be limitable which item(classes), scale and weights are allowed)
- inventory independent character/equipmentscreen
- possibility for multi inventories (e.g. multiple bags) and containers (e.g. shelves in a storage rack)
Of course, not everybody will need these features, just as with crafting or sorting. But if I’m to buy a asset, I rather buy a fully fledged system that has most of the features I want and strip of the ones I don’t need instead of one where I had to add the wanted functionality on my own. However if you can’t decide which features to include and which not you might also consider to just offer both, a simple and a advanced version of the System.