It isn't a scam to buy items from NPC shops and then look at the market boards and list the NPC item for way more then a NPC sells it. I call that the "lazy idiot tax". I did this on sargatanas for a day or so with cinnamon. NPC sells it for 4 gil but idiots would pay 200+ gil for nq cinnamon?! I'd be stupid to not take advantage of those idiots!
Also, you may want to proof read a bit before posting. You forgot quite a few words in your sentences, some sentences have a bad flow, and your subject verb agreement is rather horrendous.