Uzay: first of all, the M system tops out at 135mm, though I think there used to be a reflex system adapted for it.
I would say minimum $10K if you go with Zeiss or Voigtlander lenses. I went with a used M9, ZM21 f/2.8, ZM35C, ZM50 Planar and CV75 f/1.8 and it totaled about $9K.
