Every price sits on a ladder of round numbers, each rung 10–25% above the last, or on the lucky-nine ladder (99, 119, 149). The shop picks the opening rung and how far it may climb or fall.
The shop says how many it wants to sell each week. Selling 60–80% of that is on pace.
Over 80%: one rung up. Under 60%: one rung down. A thing sold out all week moves nothing. Orders keep the price they were placed at.
Shops pay 5% of paid sales. Half goes to the block fund, and the block’s shops vote on what it buys: shade, lights, a sign, a cleaner.
฿120
Target: 10 a week
The rule is SFpark’s, from Donald Shoup’s The High Cost of Free Parking: parking meters in San Francisco priced so one or two spaces stay open on every block, with the money spent on the block.