Singapore Airlines via DealBase offers select Singapore Airlines Roundtrip Flights to Asia and Europe with prices starting from $639.61. (On the DealBase landing page, click on "singaporeair.com" in the top line to see this offer.) That's the lowest price we could find for select routes by at least $223, although we saw these fares for $13 less a week ago. This price is valid on flights departing on May 9 from Houston, TX, (IAH) with arrival in Oslo, Norway, (OSL) with return on May 15. This sale includes flights to Tokyo, Japan, (NRT); Seoul, South Korea, (ICN); Milan, Italy, (MXP); Manchester, England, (MAN); and more. Book this travel deal by March 31 for travel through November 30.

All prices, dates, and booking details were valid at the time of publication.