A verb appearing in the Early Qenya Phonology of the 1920s with the gloss “to flap”, derived from ᴱ✶ku̯ap- as an elaboration of ᴱ√kapa “leap” (PE14/66). Oddly, Tolkien gave it the primitive form ᴱ✶ku̯api̯a-.
Early Quenya
qapta-
verb. to exchange
qapta-
verb. to flap
qaptale
noun. exchange
A verb appearing as ᴱQ. qapta- “exchange” in the Qenya Lexicon under the early root ᴱ√QAPA “chaffer” [= haggle] (QL/76).
Neo-Quenya: I would retain ᴺQ. quapta- “to exchange” for purposes of Neo-Quenya derived from a Neo-Root ᴺS. √KWAP, since we otherwise have very few words having to do with commerce.