I have been looking to get hold of a portrait lens for a few years now, something in the 75-85mm range. However, 85mm in every common mount are SOOOO expensive. Even Jupiter-9 are trading close to 80-90 EUR range. What are my alternatives? I am using with Rolleiflex with 35mm attachment at the moment. I also have a 3" projection lens that I taped inside a k-mount macro ring but of course no aperture or focus is fixed at 1m. Is converting slide projector lens a possibility?