Hey pretty cool! I like the idea quite a bit, especially since you are both buying and selling the items at your shop. One thing that did seem slightly annoying was it seemed a lot of the time I would get like 5 people in a row trying to sell me something when I had no money, and other times when I had a little money but no good ingredients. Not a big deal though since you can just "no" people and I don't think there was a punishment for that. I also like the idea that you test you weapons first!
Overall really cool and well done! Good work!