Let’s take a look at the explanation of settlement statblocks:
Base Value and Purchase Limit: This section lists the community’s base value for available magic items in gp. There is a 75% chance that any item of this value or lower can be found for sale in the community with little effort. If an item is not available, a new check to determine if the item has become available can be made in 1 week. A settlement’s purchase limit is the most money a shop in the settlement can spend to purchase any single item from the PCs. If the PCs wish to sell an item worth more than a settlement’s purchase limit, they’ll either need to settle for a lower price, travel to a larger city, or (with the GM’s permission) search for a specific buyer in the city with deeper pockets. A settlement’s type sets its purchase limit.
First, there’s a flat 75% chance of any item below the Base Value being there. This means that +2 stat items, which only cost 4000 gp, have great odds of being there, and you can retry in a week to get them if they’re not.
Spellcasting: Unlike magic items, spellcasting for hire is listed separately from the town’s base value, since spellcasting is limited by the level of the available spellcasters in town. This line lists the highest-level spell available for purchase from spellcasters in town. Prices for spellcasting appear on page 159 of the Core Rulebook. A town’s base spellcasting level depends on its type.
Secondly, the spellcasting line isn’t the caster level limit of the town, it’s the highest level spell you can buy services for. This means that the highest caster level available spellcasting services is, at minimum, 14 (the level a spontaneous caster needs to cast 7th level spells, and higher for 4th and 6th casters as all of their spells are available). The caster level for purchased spellcasting services could even be higher as there’s no minimum set for them, but it’s also reasonable for a gm to restrict this.