United has launched a miles sale promo for MileagePlus members that will award you with up to 75% more miles when you purchase miles for your account.

The promo is tiered so the more miles you purchase the better the bonus becomes.   In addition to the bonus, you’ll get 1 or 2 entries into a contest that will award its winner 1,000,000 miles which is plenty for a few First Class roundtrips on Lufthansa!

The brackets break down as follows:

If you buy between 5,000 and 14,000 miles, you’ll get a 25% miles bonus and 1 entry into the sweepstakes.

If you buy between 15,000 and 29,000 miles you’ll get a 50% miles bonus and 1 entry into the sweepstakes.

If you buy between 30,000 and 85,000 miles you’ll earn a 75% miles bonus and 2 entries into the sweepstakes.

In doing the math you’ll pay about 2.8 cents per mile (CPM) if you buy between 5,000 and 14,000 miles (plus 25% bonus).    Buying between 15,000 and 29,000 miles (plus  50% bonus) will give you a CPM of  2.3 cents.    Buying over 30,000 miles (plus 50% bonus) will net you a cost of 2 cents per mile.

The promo is set to expire on March 9, 2018.   You can buy 150,000 miles per year per Mileage Plus account, and the miles you buy do not count towards status attainment.