This is a very interesting concept. Not sure how you plan to expand on this but it feels very similar to those idle clicker game type things. Would be fun to try to optimize the most pleasure within the time limit, and fun upgrades/synergies would be cool to see, though it might not fit well with the market vibe.
The pins probably should have some sort of distance restriction to them. I would just stack 20 on top of each other and get like 2 full bars each tick.
The shopkeep design is incredible. Love them