There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
qapta
noun. deal, bargain
qapta-
verb. to 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.
qaptale
noun. exchange
qapta-
verb. to flap
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A noun appearing as ᴱQ. qapta “deal, bargain” in the Qenya Lexicon under the early root ᴱ√QAPA “chaffer” [= haggle] (QL/76).
Neo-Quenya: I would retain ᴺQ. quapta “deal, bargain” for purposes of Neo-Quenya derived from a Neo-Root ᴺS. √KWAP, since we otherwise have very few words having to do with commerce.