So I am a little confused by the Core Rules Books definition of Craft (Alchemy);
To make an item using Craft(alchemy), you must have alchemical equipment. If you are working in a city, you can buy what you need as part of the raw materials cost to make the item, but alchemical equipment is difficult or impossible to come by in some places. Purchasing and maintaining an alchemist's lab grants a +2 circumstance bonus on craft(alchemy) checks because you have the perfect tools for the job.
If you have the Alchemist's Lab can you assume you "have alchemical equipment" already? So alchemical equipment wouldn't need to be sold in that area for you to craft items?