I am selling as I am putting bike back to standard, possibly to sell her onwards but hopefully not if I can keep her.
I found the screen worked well for me at the two highest vane settings, where it was noticeably better than the standard setup. Larger screens such as the Givi d129 I also had offered more protection but also quite a lot more wind noise, even with earplugs fitted.
Is it expensive? Only if you don't get on with it & no-one will buy it off you 2nd hand. Which I suspect won't happen, these screens are fairly popular with good reason.
There have been numerous threads on screens for the Fazer1000 but I personally think you have touched on the main problem - the Gen1's fairing area is quite small and sits out quite a bit in front of the rider, so there will always be some turbulence.