Age helps, but it’s not the only deciding factor.
Call Sky Insurance and have a chat, I expect they can provide you a quote if you find an example car.
I’m 26, my JZX100 is about £60 a month. It used to be garages but that changed when I moved, the insurance hasn’t gone up by much. It might help that mine is N/A auto, but it’s still a Japanese Import, modifications only cost the admin fee as far as I’m aware.