Prohibition on increasing prices for one who does not intend to buy the product
Question

                There is a person who attends auctions and increases the price of the goods, but he does not intend to buy them. What is the ruling on that?.
Praise be to Allah.
    If a person increases the price of an item that is offered 
    for sale when he does not intend to buy it, this action is haraam, because 
    it involves cheating and deceiving the purchaser, as the purchaser may think 
    that the other person only offered this price because it was worth it, and 
    that is not the case. This is the artificial inflation of prices which was 
    forbidden by the Messenger  (peace and blessings of Allaah be upon him) 
    as it is haraam. It says in the hadeeth of Ibn ‘Umar (may Allaah be pleased 
    with him) that the Messenger of Allaah  (peace and blessings of Allaah 
    be upon him) forbade artificially inflating prices. And it was narrated from 
    Abu Hurayrah (may Allaah be pleased with him) that the Messenger of Allaah 
     (peace and blessings of Allaah be upon him) said: “Do not go out to 
    intercept the riders (for trade), do not outbid one another, do not 
    artificially inflate prices, and no town-dweller should sell on behalf of a 
    Bedouin.” Agreed upon.  

    If it is proven that the price was inflated artificially, and 
    there was some deceit involved in the sale that was out of the ordinary 
    (i.e., some cheating in the price), then the purchaser has the choice 
    between cancelling the deal or going ahead with it, because that come under 
    the heading of being given the choice in the case of cheating. End quote.