That doesn't surprise me, but it depends on usage, eg if it's on historic (club) plates and limited miles per year, where it's normally parked etc.
My 750 costs $60 and my 400 $50, with $100 excess and no theft excess.
I've never made a claim with them, but I hear they are very easy to get along with.
I guess it's so cheap cos us fanatics are pretty careful and look after our toys, and the damage claims are fairly few.
Peter.