House 3: May Fall Through (Updated)

I just found out that the buyer's lender found out this property was a flip and they want an addendum to the contract. The addendum states that I will sell the house for whatever the appraisal comes back at (or $205,000, whichever is less) AND I will still contribute 3% of the price.

There is no way any seller in their right mind would agree to this. Suppose the appraisal comes back at $175,000? I'm not going to agree to sell the property for an unknown amount determined by some stranger that is paid by the buyer. That conflict of interest seems pretty clear to me. My agent thinks the buyers will have to back out if I don't agree, but so be it. I rejected the addendum and my agent is moving the listing status back to active.

Update: Things are changing by the minute. My agent talked with her broker about this addendum and we all agree it's poorly written and there is no real need for it. The addendum actually states that if the appraisal comes back for less, than I will still contribute 3% towards the selling price. It doesn't actually specify a selling price and leaves things very vague about what happens should the appraisal not match the selling price. But this is unnecessary because the standard sales contract already includes a clause where if the appraisal doesn't match the sales price, the parties can renegotiate or cancel the sale.

How funny! I just got another call. Turns out, the buyer's agent didn't know that the standard sales contract was contingent on the appraisal! They are happy with that and are ordering the appraisal now and are moving forward without the addendum. I asked if this was a new agent and my agent said it was. And it was the buyer's mortgage broker that asked for the addendum to be written in the first place. So it appears we were just dealing with some uninformed people. Once things were explained, the problem went away.