Unless you desperately need a home to live in (NOW), IMO you would be an idiot to offer more for a house than you think you could sell it for next year (or next month for that matter).
IMO It’s like going to the store hungry, your not going to make the best choices for food purchases. You got to be willing to walk away if the price is not where you will be able to resell it and get you money back.
(this includes all other costs, so you will need at least a 10% – 15% cushion in most cases IMO).