Some of these are kind of funny

Immensely splendorous payment. Correspondence was state-of-the-art. Recommended.
Very, very first-class payment. Recommended. Thanks. Correspondence was elegant.
Choice payment. Transcendent correspondence. A remarkably optimum buyer. Thanks.
Remarkably quick payment. Correspondence was standout. A notably greatest buyer.
Very speedy payment! An immensely excellent buyer. Distinguished correspondence.
Exceptionally transcendent payment. Matchless buyer. An ever so admirable buyer.
Notably august payment. Splendiferous correspondence. An ever so peerless buyer.
Wonderful payment. Superlative buyer. Correspondence was estimable. Recommended.
Payment was ever so swift. Thanks. Correspondence was stunning. Notably pleased.
Notably quick payment! Correspondence was peerless. A very, very choicest buyer.

Notably dull payment. A remarkably indifferent buyer. Exceptionally indifferent.
Ever so colorless payment. Unexceptional correspondence. Remarkably indifferent.
Remarkably fast-ish payment. Buyer is typical. An immensely unexceptional buyer.
Immensely slow-ish payment. Ordinary correspondence. Correspondence was humdrum.
Notably intermediate payment. A very indifferent buyer. Standard correspondence.
Payment was exceptionally slow-ish. Wish all buyers were this characterless. Eh.
Slow-ish to pay. Exceptionally indifferent. Wish all buyers were this colorless.
Immensely moderate payment. Correspondence was humdrum. Standard correspondence.
Exceptionally conventional payment. Oh well. Correspondence was run-of-the-mill.
Mainstream payment. Eh. Correspondence was indifferent. Mediocre correspondence.