Ann: Primobius - 50tpd Spoke Engineering Cost Study Results, page-59

There is more to it than this.

#1 CAPEX are shared through JVs
#2 $27 million/year is not a fully established figure as we don't know the OPEX for the HUB. If it is under the $4,000 used by @quizmaster888 then profit would jump even higher
#3 This is for one plant only. They have 4 on the way totalising 120tpd
#4 The whole point of the system is to be scalable and reproducible worldwide. In other words, more plant = more $
#5 We haven't yet established the revenue generated by the other 2/3 produced by the Spoke (the non black mass stuff)
#6 4 years to fully pay for a plant is actually a great score. Imagine after 4 years!