In common commercial english, i would read that as “this merchant will offer to trade any of the books for an amoumt of currency equal to half the book’s cover price plus $1.”
Such vagueness also suggests sufficient informality that the merchant may either accept seperate offers or veto the general rule on a case-by-case basis.
Nancy Pelosi also said that we have enough votes to take the house.
I’ll consider listening to her again if and only if Hakeem Jeffries is Speaker.