I went to AC.ca last night to buy a ticket (would have bought on WS.com excewpt WS has no late service for YVR-YLW). Tango fares were available on both legs but when I selected to buy, there was one of the frequent technical errors and when I tried to find fares again, the Tango fare on the return leg had disappeared.

Deterred from buying immediately by the $20+tax fare increase, I went to look at destina.ca, various regional flavours of expedia and travelocity and even AA.com to see if I could get a lower fare to no avail. Going back to AC.ca after some 10-15 minutes, I did a fare search again and the Tango fare that had disappeared appeared, but of course another technical error cropped up.

Anyway, I figured that the fare would cropped up again so after refreshing the fare page every few minutes, the low fare popped up again and this time, I managed to buy the ticket.