Avianca LifeMiles is offering a bonus of up to 145% on purchased miles through November 27, 2017 (this Monday). You'll need to sign into your Avianca account to view the sale. You can buy up to 200,000 LifeMiles during the sale and get up to 290,000 bonus miles (for a max total of 490,000 miles). This is nearly as cheap as it gets. The cheapest I’ve ever seen LifeMiles was 1.32 cents each. But what sets this sale apart and makes it better than past sales is that bonus is not tiered.

Alaska Airlines MileagePlan is running a 40% bonus sale, available to the first 2,500 MileagePlan members who take action. You can buy 10,000 Alaska miles at a time that will come with a 4,000 miles bonus. If 2,500 members don't purchase sale miles by 11:59pm on May 3, the promotion will end then.

Including taxes, you'll pay $295.63 for 14,000 miles, or 2.11 cents per mile. We've seen Alaska miles on sale with as much as a 50% bonus, allowing you to buy them for 1.97 cents each.