I have a HJC FS-MXN with my DT300i. The opening and closing mechanism is easy and reliable using one hand.
I paid 165 € (euros) for it last week.
It isn't very noisy when it's closed and its ventilation is adequate On streets I always wear it open with the solar second visor. And I can put it on without taking off my eyeglasses, it's an important point for my use.