From now till 24 December 2024, buy Marriott Bonvoy points with up to a 45% bonus, with an extra 1,000 points for a minimum transaction of 20,000 miles.

source: https://milelion.com/2024/11/06/marriott-bonvoy-offering-up-to-45-bonus-on-points-purchases-with-increased-annual-limit/