The Mega4.5DD mask was around $200. The mask has a range of diopters it can correct for without contact lens. For my age (40+) it works without contacts from -4.00 to -6.00. Check out the link below for more info:
Diving Masks by HydroOptix -- Products -- 4.5DD Rx Conversion Chart
It also comes with some snap on lens (and a mount for your BC) for use above
water. Another great thing is that mask is incredibly clear compared to the plastic masks out there. I've always been afraid to dive with contacts because if I lose them under
water, I'm mostly blind. This mask is very reassuring for me in that sense.
I'm not sure if I believe this but the DM at the dive shop was saying that many people with near perfect vision have bought contacts just to use this mask. Who knows.....