price = base × scarcity × momentum
- scarcity(1 + sold ÷ total) ^ 1.6
- The fewer of a size left, the more the rest cost. Sell out a size and it ends up roughly three times its starting price. Each size is counted on its own, so a rush on the big slots never makes the cheap ones dearer.
- momentum1 + 0.6 × min(1, sales₂₄ₕ ÷ 40)
- When the board is busy, everything costs a little more, up to 60% more on a very busy day. Nothing has sold in the last day, so this is not adding anything right now. It drops back down on its own when things go quiet.
Whatever price you are shown when you start paying is the price you pay. It cannot change once you are in checkout.