Okay,
So since the trading post is for trappers, seriously in an area this small unless the trapping industry is huge (selling MANY pelts for HIGH prices) that trading post is going to be turning itself into a general store to cater for the farmers as well. You'd be a maniac to be the only obvious store in a village and not sell some staple spices (salt, pepper at least), foreign staple goods (flour, rice, barley, oats or other grains not locally grown), animal meat (from the trappers) and general equipment (hammers, nails, saws, shovels, hoes, horse tackle, clothing, boots, gloves, knives, plates, metal cups, etc). From an economics point of view you should really consider that trading post as a the local general store. If it is the only store, it will also probably be the point where any coaches/stages travel past and will likely be on the busiest road in the village. If it is NOT the only store, then your map should include a general store and potentially have a few rooms for rent attached to the store.