Star Trading

A game of supply and demand amongst the stars. Each player controls a merchant spaceship and is trying to but low and sell high by traveling from planet to planet.
Each player starts with one ship which is placed on the map on one of the outer planets. Each player's ship starts with 5 movement, 3 cargo space and 0 attack. Each turn a player may move the speed of their ship and may buy or sell any amount of resources and may buy new ships or upgrades for their current ship. This steps may be taken in any order but buying and selling can only be done on planets.
Players may also build trading posts which allow a player to trade and buy resources on a planet without having their ship there.
There are five different resources, Food, Minerals, Luxeries, War Materials and Manufactured goods.
Each planet values each resource differently. Each turn the global price goes up or down by a random amount for each resource (roll a dice). Each time a player sells a resource at a planet the price of that resource at that planet goes down, each time they buy the price goes up.
Food is worth 10, Minerals is worth 20, Luxeries 50, Manufactured Goods 50, War Materials 75. Food fluctuates by one up or down each turn and is lowered or raised one up or down each time it is bought or sold.
Minerals fluctuate by 1d6-4 each turn and each time it is bought or sold it raises or lowers in price by three.
Luxeries fluctuate by 1d10-6 each turn and each time it is bought or sold it raises or lowers in price by five.
Manufactured Goods fluctuate by 1d10-6 each turn and each time it is bought or sold it raises or lowers in price by five.
War Materials fluctuate by 1d20-11 each turn and each time it is bought or sold it raises or lowers in price by five.
The game ends after a certain number of turns, maybe 15 or 20. The player with the most money wins the game.