Cool game. I played until the end of Day 3. Here is my feedback.
- The gameplay loop seems to revolve around providing as many types of items as possible to ensure that all customers get what they want. In itself, it's not very engaging. I can influence neither the price of commodities, customer preference nor physical location of the commodities. It doesn't make for an engaging experience when the only thing I can do is showcase as many items as possible and hope for the best.
- Comparing your game to another RPG Shopping simulator" Recettear" would be a good start. In recettear, you can negotiate with customers and each customer has different mechanics that you can exploit. Location such as near the cashier or the entrance would allow you increase the price of your selected commodity. Getting the goods also involve hunting the goods in another dungeon as opposed to ordering from a bulk supplier.
- If you didn't tell me I am selling stuff the to the bad guys, I wouldn't know. As far as i know, I am selling potions and gears to adventurers. if you want to make me feel like an evil shopkeeper, make it clearer that I am selling controversial things like Monsters, Slaves, tomes of dark magic or torture devices, not the standard RPG adventurer gears!
Other than that, the description of your project is clear and concise, with clear headlines followed by bullet points.