I don't know the answer to this, but the problem is, a lot of players bypass the average range of 90 - 100 points (which is 500 - 560K) on their way to the top 10.
Oliver did it from 70 average, Petracca from 81. Walsh just missed this bracket on either side in his first 2 years (86 and 101), then went 117.
None of this years top 4 mids ended a year in that price range to even compare trajectories. Jack Steele did 95 to 122.5 in one jump, but he spent 3 years in the 90's before doing it (probably tagging).
It comes down to talent (usually a high draft pick), opportunity in the right role, and the fitness level to play the TOG required. They all have the first 2, but some players take longer than others (Petracca, Dangerfield, Miller) to reach the running capacity needed.
You really do need to hear that they are flying in pre-season, then see it with your own eyes in the practice matches. Then **** your pants and just pick the expensive guys.