United Airlines is offering Mileage Plus members the opportunity to earn double elite qualifying miles on all paid United flights through Dec. 15.

But you’re going to have to pay for the privilege.

A one-time fee of $100 will ensure that your quest for Premier, Premier Executive or 1K status will be significantly shorter.

It bears repeating that elite qualifying miles are harder to come by these days. Both Delta and Continental have restricted the opportunity to earn status miles on lower-revenue tickets. As a result, the hallowed “mileage run” — the annual tradition of bulking up on inexpensive flights at year’s end in order to re-qualify for elite status — may be on the verge of extinction.

United’s offer guarantees that regardless of what happens next year, at least this year’s mileage run will be cut in half.

To take advantage of this offer, Mileage Plus members must register at http://www.united.com/doubleEQM, enter their Mileage Plus number and pay the fee.