TAP Air Portugal frequently runs buy miles promotions but their Cyber Monday offer for this year is one of the best yet. When you buy at the highest level, 20,000 miles for 700EUR you’ll get that amount quadrupled. That means you would receive 80,000 Miles&Go miles for 700EUR. This means you are buying each mile for 0.875 Euro cents each. This offer is available until Dec 1, 21.