They also seem to like to tinker with incentives within incentives. Lately, they have switched between 150 or 200 points being the sweet spot. After the deep discounts they had for big purchases, they have been cutting off discounts for larger point purchases and I wouldn't expect that to change much, especially this period and with the price increases.
Only mention it in case you like the incentives based on the points you intend to purchase (150 vs 200 etc) vs are holding out for a better deal on some more points.
Agree with everyone here, just get an email from a guide locking in incentives if you intend to purchase short term.