For me it really has to do with the price of the product and if I think it is fair. I have no issue paying the asking price if it seems fair. If it seems high I will offer a lower price than I anticipate paying to leave room to negotiate. If the seller does not want to move, fine, I will move on.
As to those who get insulted by an offer, frankly as long as it is presented respectfully, they need to get tougher skin. The very fact you are putting things up for sale means you are inviting offers, you should be prepared. Doesn’t mean you have to accept it, but you should anticipate offers lower than what you want to sell for.
