I have a mamiya 645 w/ Sekor-C 80mm lens, but the lens has been dropped and does not focus easily (not at all) and the shutter sometimes sticks and leaves me with half and half frames. I like the system and am considering upgrading to a Hasselblad. 500cm? Is the 500c cheaper? I will probably be using the Zeiss Planar-T 80mm/2.8 with it. Is this a good starter kit? Thanks.