This has happened to me before so...what I do is to ask them if they have perhaps made an error in judging postage as you have had many dealings involving chips and the cost is usually around $3.00.Tell him that you think that $9.00 is too much and that you do hope that they can check out the actual cost.
This works,as I have always had sellers reduce their rates.
Also,if this does not work,then I would tell them that $9.00 is way too much and that you cannot justify spending that type of postage charge.If he does give you a neg,then explain that his postal charges were exhorbitant and just go one with your day.