Editing Trinity:City Mechanics (section)

===Infrastructure===
Every standard item has an availability rating, on a scale of 1-100. Any item whose availability rating is equal to or below the city's Infrastructure can be purchased in the city at the city's price for the item (standard price modified by Economy).

If an item's value is below the max GP limit for the city, but its availability is higher than the city's Infrastructure, the item can still possibly be found, but at higher prices than normal. To do so, follow the following steps.

# Determine the Craft skill that would be able to produce the item. If the city has the skill, proceed to the next step.
# Multiply the city's skill bonus in the skill by 5.
# If the result is higher than or equal to the item's availability, the item can be found in the city.
# Subtract the city's Economy from the result in step (3). If the result is below 1, the item cannot be found in the city. If it is 1 or higher, subtract it (as a percentage) from the city's currency value.
# Divide the item's cost by the result in step (4) (as a percentage).
# The result in step (5) is the cost of the item in the city.