And lo, the ships come in on the flooding tide

Potential mechanisms:

Goods arrive by ship in an (2(N+1)) wide stream. The goods are ordered across the width of the stream. Possibly there are two streams.

Players compete for order of purchase to those goods via auction. The auction winner may pick which stream (ie ship) to buy from. Goods are purchased in adjacent pairs. The winner of the auction may buy 1 or more pairs from the right at his price. If any are left the next player in the auction may likewise etc until either all goods are gone or all players have had the option to buy. Unsold goods are dumped in the bank’s supply (ala 18XX). This is essentially the equivalent of a n Operating Round in the 18XX.

Next is a Stock Round. By the end of the Stock Round each player’s holdings must entirely fit within their warehouses. All other goods must be sold. On their turn in a stock round a player may sell goods at the current price, buy goods at the current price, and sell goods at the current price (seel-buy-sell in 18XX parlance).

Movement:

– Sales move down immediately – Unbought goods after stock round (from sales or left over from auction) move left – Goods sold at auction and none left after SR move right – Monopoly held in warehouses after SR move up – No buys moves left.

Player’s have warehouses of limited capacity. Later in the game they may purchase additional/larger/expensive warehouses. By the end of the stock round players may only only the goods in their warehouses.

Feedback loop needed for future goods.