In fact, don't base your offer on the asking price at all. Base it, instead, on the value of the property. Have your Realtor pull the comps to determine what the property is really worth in its present condition. It may be significantly more or less than the asking price.
Once you have a good sense of what the property is worth, don't pay any more than that. Your offer might be at that amount, or it might be less. Your Realtor can provide guidance on bidding strategies. But you have to begin at the property's real value, not its asking price.
Hope that helps.