I am not sure how long you have been looking but historically,it takes about 3 months for a buyer to have viewed enough homes to know if a home is priced correctly. It appears you have a sense of the market in knowing this may be priced a little too high
If you are working with an agent, they should be able to provide comps so you can see (just as sellers do) what changes are occurring. Keeping in mind, location is the number one factor in determing value (and the one factor you can't change after you buy a home) . What you need to go over is :How is the condition of this home? Has it been updated? Does the floor plan work for you?
Do you have a copy of the disclosure to see the history on this home? Condition of a home is one factor that does not show up when you review comps of like homes--only having seen the home (yourself or with an agent) can you factor that into the price.
If this home is the 'one' for you, and you have spent time looking at similar homes in the area, writing a realistic offer, even if its lower than asking, should not be offensive but rather should get the seller talking to you. Again, an agent whose job is to know their inventory can be an invaluable resource assuring you that the offer you put in is realistic. In addtion, the negotitation skills of a good agent can help bridge the gap between the price the seller has set and the one you wish to pay.