Normally:
WPM = ((amount spend on keyboard)/2) + 20
For Topre:
WPM = (((amount spend on keyboard)/2) + 20)*1.1
There is a lot of research on the ergodox. But early estimations indicate that when used over a long time, actual WPM could be over 9000. But you have to take that with a grain of salt as it is mostly based on anecdotal evidence from ergodox owners.
You missed one of the most important calculations to get WPM.
Once you have your base WPM from the equations above, you must then add the result from the Clackdratic equation: y = ax^2 + bx + c
a represents the total number of artisan caps (inclusive of Bro Caps and Clacks)
b represents the total number of Bro Caps
c represents the total number of Clacks
x represents the amount of money you have spent on your artisan caps
y represents your WPM
You can see from this calculation that as you accumulate more artisan caps, your WPM increases exponentially.
This is extremely dangerous because once you reach even 5 artisan caps, your WPM gets so high that you must deliberately type slower to avoid melting your caps (even your artisans) from the sheer heat generated by your typing.