I forgot to add prices for the greatcoat and a RPGSite forum-goer suggested I add a breastplate, which is a great idea.
Greatcoat AC +2 Cost: 20 gp
A greatcoat is a leather trenchcoat that reaches down past the knees.
Breastplate AC +4 Cost: 35 gp
A breastplate is a solid piece of metal armor covering the chest