Excellent, good show.
The keywords we are trying to rank for, MOZ says it has a 28% difficulty, so I do not think we will need a 79/82 horsepower to rank on page 1 in a good position. I suspect that since DA is calculated on a log scale, the difficulty % is also probably logarithmic, so a 48% difficulty would take quite a lot more DA to rank, than just a linear interpolation would suggest for a 28% difficulty.
I wonder if you can approximate how much DA/PA it takes to rank at a given difficulty % - have you ever given thought to this?