Hi,
The entry level Mamiya ZD with body and lens will set you back by about US$10K. For Phase One back 22MP, with body and standard lens, this combo will cost just over US$20K. Therefore, given it is a Leica, US$20K+ sounds reasonable. If you need 39MP, the Phase One will cost over US$30K. A week ago I received an email from the local Hasselblad's agent offering the HDII-31 Kit for SG$30K. This was very tempting, but I can buy the same kit for US$17K in the US.
Since I am a R user as well, I will be anxiously waiting for the launch of the R10.
N.S.