A root in the Qenya Lexicon of the 1910s glossed “chaffer”, which is an archaic word for “haggle”; it has a number of derivatives having to do barter and bargaining like ᴱQ. qampo “pedlar, huckster”, ᴱQ. qapta “deal, bargain”, and ᴱQ. qapta- “to exchange” (QL/76). These early words have no clear replacements in Tolkien’s later writing, so I recommend positing a Neo-Eldarin root ᴺ√KWAP to salvage these early words.