Originally Posted by coolcoil

Are the taxes comparable? Colombian airport, resident exit, and sales taxes typically add $150 or more on top of the fare for my flights.

You may also want to look at booking through UA even though you have had issues with them. For my two trips this month, booking a UA ticket on all-COPA metal saved $200 on each trip (MDE-IAD and MDE-IAD/JFK-MDE). I have no idea why UA would have COPA inventory cheaper than COPA, but sometimes it happens.