I like LIFO. I think it's better for the game, better for the strats out there, and better for the tactics it could provide.

FIFO
First in, First out. The first goods to reach the market are sold first based on price. Leads to nothing significant to detect on the market, and sales only for the sake of selling or storing.

LIFO
Last in, First out. The latest goods to appear on the market are sold first based on price. As a result a players goods can become stuck. Market players can play it to advantage, a tactical 4hr play. Everybody else can see the caps and decide what is worth buying or not.