IMO, whenever you can get < 1 cpm, I would do it. But that is because I value my AP over >= 1 cpm.

If I understood correctly, if you spend "x" to get 4200 AQM, you will get the 150K Threshold bonus. So, that means you will get 154200 in total (or 158400 if you select the 100% in bundle 1), hence if a is flight $1542 (or $1584) or less, I would go for it under my own value of AP.

​

​​​​​