That's the lowest price we could find for select routes on comparable 5-star carriers by $121. Buy Now at DealBase Tips On the DealBase landing page, click on "Singapore Airlines" in the top line to see this sale. We found this price on flights departing on August 6, 2020, from Seattle, WA (SEA) to Manila, Philippines (MNL), with return on August 24, 2020. Book this travel deal by October 31 for travel through August 31, 2020. All prices, dates, and booking details were valid at the time of publication.