The whole point of placing an offer is that you are offering to pay what you think it is worth and are happy to pay for it. To an extent, nothing else matters...if you want to live there and think its a fair price.
Or you are offering what you think the buyer would accept, given a few things...
how long the place has been on
how many times the asking has been reduced
the general state of the market (up or down)
the long term outlook for houseprices (good or bad)
The whole point of placing an offer is that you are offering to pay what you think it is worth and are happy to pay for it. To an extent, nothing else matters...if you want to live there and think its a fair price.