The PM price of bushels with no Military tech is $29
For a Democracy, you need Military at 81.69% to get a PM price of $36, because:
$29/0.8169= $35.5006, and the game rounds this up to $36
For other government types the maximum is $35 because only a Demo can go as low as 81.69% Military
You can find the amount of Military tech needed to get 81.69% with a Demo based on your land using the EEStats tech calculator, which can be found at https://www.eestats.com/techcalc.
The same calculation is used to get the PM bushel price with any government type and Military tech percentage. It always rounds up when you are at $34.500001, $33.50001 etc. Similar calculations are used for all PM prices.
Also, Marshal is a spamming idiot and should be banned from this thread.