Er, you don't want to just buy off the market and put it back up instantly.
Wait until the item is at it's lowest price in fluctuation, buy it. Then wait until it is at it's highest price in fluctuation to sell it on the market.
Most people in the toribash community use the term marketing for the general trading and profit related business, so I decided to name it a marketing guide since it's technically more towards the side of profitable trading techniques.