Is there a success fee when my Fixed Price Offer is accepted for a Car listing that did not sell?

I had my car auction close without meeting reserve. A watchlister has requested a Fixed Price Offer (FPO).

There is a disclaimer when making this offer:

"If the offer is accepted you will be charged a success fee. Making this offer represents a commitment to sell at the stated price"

I can't find an answer as to how much this fee would be, and I only know what there are no success fees for car listings as the listing fee is paid upfront. Does this also mean there is no fee when making an FPO?

Thanks in advance