84,000 Euro is $113.000 CDN
If you want to build a competitive TZ750 it would be easy to spend that.
The CMR/MOJO FJs that went to Phillips Island weren't $100,000 each... but close... and MOST of the engineering that went into those bikes was done Pro Bono (and there was a LOT. Custom EVERYTHING)
Patons are very special bikes. Frames by Tonti (the guy that did all the GOOD Moto Guzzis) and the suspension design started from a blank page (VERY rare in Vintage racing)
There is a street version, powered by a Kawi 650 twin, that sells for a lot less. The Paton that Dunlop won the 2018 lightweight TT on was based on the street model (and you can buy a copy of THAT bike for about $40,000USD).
Racing ain't cheap... but in vintage racing: you don't have to buy a new bike every year. You just keep flogging it till you figure it out... or, the more popular route, you run out money and motivation
How do you end up with a million dollars from racing?
Start with two million dollars...
I betcha CMR/MOJO spent most of a million going to Phillip Island in 2019... for ONE race.