She'll accept his offer on the grounds that they're worthless to her if they get tracked down by the owners/manufacturer (and will say as much to avoid coming off as too naive in accepting his price), happy to do one another a favour in selling at a price that suits him.

Though she'll add that she's going to need compensating for her time and effort and that a drink should cover her fee, hoping to build a little on the foundations of the sale with a chance to sit down and make an impression.