Your interests will be served best if you have buyer representation, and the agent representing you is familiar with the negotiating process.
January through April 16 data in MLS reflects an average of 96.1% sold price to list price ratio for single family homes (ie 3.9% below asking price). For condos its 94.12% (ie 5.88% below asking price).
Your best bet for negotiating is to form a strategy with input from your real estate agent for the particular home you are interested in.
Paul, ask your Realtor to find out what the history is on the home. When did it come on the market? What did it sell for on the last go around? How many offers have the sellers had? Are there any offers on the table now? The more information you have, the better decision you will make.
The question you need to ask yourself - How much will this cost me if I do not buy this home now? See my blog at: http://www.ronmersinger.blogspot.com/
Keep in mind that the seller does not walk off with the total amount on the executed agreement for agreed purchase price. The seller stills needs to pay for real estate taxes, insurance, realtors fees, closing costs and etc.