I'd budget worst case about 1500.
I went back to a bike in 2015, no NCB, I was 29 at the time, but had my full license about 7 years at that stage. Insured a new Multistrada 1200s for €1500, which while not a full sports bike is still a high grouping and it was worth a lot at the time.
Insurance has dropped since so I can't see it being worse than that.
It's worth sticking it out whatever it costs. I still have the same bike, it's now 6 years old and with a full NCB, it's now €320 to insure fully comp.
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