Figure an asymmetric collection of trade goods; some fairly linear set of distributions, not a lot of variance but enough to be significant. A few more of some than others. The total number of goods cubes would approximate ((2N)+M) where M isn’t large and N is the number of players.
Trade goods are cubes. Simpler that way.
A grid of cards 2N+1 wide and 3 deep is laid out. Two cubes are placed on each card. A card represents a ship arriving in the harbour. Each row of cards represents a full turn of the game. The remaining goods form the supply from which future row/sets will be drawn.
First turn turn order is determined randomly?
Each player has an identical set of cards, each card identifies an auction type (Vickrey, Dutch, English etc). each player also has one warf card.
The first player from the last turn selects an auction type and discards their card for that auction type. if the first player has no more auction cards then they select an auction type from the first player in turn order who has an auction card left. An auction is held in accordance with the card to determine turn order. (Dollar auction bad) In turn order each player moves one of the bottom row of ship cards to an empty wharf card in front of them (possibly to another player’s wharf?). This continues in rotation until each player has one ship per wharf. This represents a ship docked at that player’s wharf. The ship which wasn’t selected is emptied into the bank and the prices for those goods moved down as if they were sold.
In rotation each player:
a) optionally sells one or more cubes from their warehouse to the bank and instantly moves the market value down one row per cube sold
b) buys a cube from a ship in front of another player for the current market cost of the cube (cash paid to other player)
simply moves a cube from the ship at their warf into their warehouse for free (if there’s room)
buys a cube from the bank for market price and moves it into their warehouse (if there’s room, cash paid to bank)
buys a warehouse (stores additional cubes)
buys an additional wharf (limit on total number of warfs per player, possibly with a limited upgrade path, possibly with a rusting mechanism)
c) optionally sells one or more cubes from their warehouse and instantly moves the market value down one row per cube sold
The player may not buy a cube of a colour they have sold in that (larger) turn. They may sell cubes from their warehouse. This repeats until all players pass. Once a player passes they may not perform further actions. Any cubes on a player’s wharf when they pass are dumped to the bank for no money, but the market value is reduced as if they were sold. Market prices are then adjusted according to the market activity and any cubes in the bank are returned to the supply. A new row of cards/ships (number of warfs in play plus 1) is then laid above the other two rows and filled with two cubes each per card, thus setting the ships for 3 turns hence.
Repeat for N times the number of players turns.