Merchant Archive

I'm a doctor and hate to sell things. I know this is where the merchant comes into play. What I don't understand is how you make your money out of it or am I lossing money by having you sell it for me? Can anyone give me an example of how a resell would work if lets say the item is valued at 10k. Do I sell it to you for 10k or do I sell it to you for 9k and you sell it for 10k?

For example I go to novice archtecs shops selling things for way cheap buy them out sometimes this is over 100+ things go back and sell what I bought from him for usely 2 times what I payed for it. And becuse I have Advertiseing 3 And can be on the world map people come to my shop inted of his lame bisness dr0id term. that's how it works