Yes, you can. It is a pleasure, but there is a case that several prospective buyers are found through the real estate company which requested sale. In that case, it is possible to raise a sale desire price. However, it is not clear whether the buyer candidate wishes to purchase even if it is the price which raised.
On the other hand, lowering the asking price of sale is frequently done in other transactions. If you wish to lower the price based on your own judgment, do not hesitate to contact the person in charge of the real estate company and discuss how much of a price reduction would be appropriate.