My advice would be to sit down with your agent and pull up the last 30 days of sold's in a 1 mile radius of the house you are thinking of writing (be sure not to cross any major boundries, your agent will know what these are) an offer on and let the market answer that question. You may find that it is not in your best interest to offer under asking at all, it may be better to come in at asking or slightly over.

Hi Vigalz11,
You should offer what you feel the home is worth to you. There is no magic formula in this market to offer and be accepted. Remember, you can always see if the seller will counter-offer or if the seller does not counter, you can submit a better offer if the first is rejected.
Good Luck!
Anne Wanchic
The Realtor Referral Assistant