There really is no firm answer to this question. It all depends on how the asking price reflects the market in your area. If the asking price is low when compared to recent sales of similar homes in the same area, you may be getting a bargain at the asking price so you might want to start and end there. If the price is very high, a bid of 10 or even 20 percent below the ask could be called for. The best thing you can do is to look at recent home sales of similar properties in the area and see how the asking price compares to the prices those homes fetched. Generally, you will have a better idea about what these "comparables" really mean if you look them over with a real estate agent or an appraiser.