United’s latest mile sale for Mileage Plus comes to an end at midnight on September 26.   Between now and then, you can save up to 30% on the miles you need.

Specifically:

Buy 5,000 – 14,000 miles and save 15%
Buy 15,000 – 29,000 miles and save 20%
Buy 30,000 -150,000 miles and save 30%

Remember, you can buy up to a maximum 150,000 miles a year per account.   They have a pretty good rate of return when they convert into First Class tickets on Lufthansa!