base value 200gp. (scrolls, potions?)
So what the below means: right now you can only buy items less then 200gp at a 75% success rate per month. You need to build some econ buildings that add to base value to increase this number. The magic items slots buildings provide are above and beyond the base limit. These item are "donated" to the city. These items were found, accidently created, part of some maglings term paper etc.
Importing goods: The town of Restov is available for placing special orders. They have a base value of 8000gp. There will be a 10% fee for anything purchased this way in order to provide the extra security needed to get such valuables through the stolen lands.
Exporting: In addition to being able to sell item for build points, you can export items worth less then 20,000gp. This too will come with a 10% fee.
When using these rules to build a settlement, the city’s
base value (see Pathfinder RPG Core Rulebook, pages 460–
461) starts at 200 gp. It increases as you construct certain
buildings, like shops and marketplaces.
Base Value: The base value associated with a city
built in this manner is tied not to its size but rather to
the number of Economy-based buildings it has. Each
such building, whether it’s a shop, tavern, or brothel,
increases a city’s base value. Any magic item equal to
or lower than this base value in cost is available for
purchase 75% of the time—this check may be made
again every month (as new stock comes and goes). Any
nonmagical item from the equipment chapter in the
Pathfinder RPG Core Rulebook is always available if its cost
is lower than the city’s base value. Cities with multiple
districts add the individual base values of each district
together to determine the entire city’s base value, with
an upper limit of 16,000 gp per city.
Magic Item Availability: A certain number of more
powerful and valuable magic items are available for
purchase in any city, although these items tend to be
of a somewhat random nature as new items are found
or created and enter the economy. As with base value,
a community’s size does not influence the number
of magic items above base value that are available for
purchase. Instead, these items become available as
certain buildings (like academies or magic shops) are
added to a city. Whenever such a building is added
to a city, place an “X” in one of the boxes next to the
appropriate item category to indicate that the city has
gained a “slot” in that category. During every Upkeep
phase, randomly roll a magic item of the appropriate
category for each empty slot.
After it is generated, a magic item remains on the market
until it is purchased. Alternatively, once per Income phase,
a kingdom can make Economy checks to try to sell items;
once the item is sold, its slot remains empty until the next
Upkeep phase (see page 61).