TL;DR I am afraid that you need to evaluate the lenses individually.

Rangefinder an DSLR lenses are often different in construction because both have different design goals and restrictions. RF lenses are often made to be smaller. RF lenses cannot be used from very close proximity, so no corrections or compromises for very close range are necessary. RF lenses, especially those intended for use with film, can have the rear element placed very close to the film/sensor. So these are often different constructions and therefore there will be differences. Since you ask about performance on a mirrorless digital camera - wider angle lenses (usually under 50mm) designed for RF can have reduced performance on digital cameras due to proximity of the rear element to the sensor and the oblique angle under which the rays reach it. Notable exception here is Leica M with sensor design that can handle that for all but very extreme cases.

The price differences between used RF and SLR are most likely commanded by the demand, but there is one technical difference that could support higher cost of RF lenses - rangefinder coupling. When you turn rangefinder lens, it's exact focusing position needs to be mechanically transferred to the camera rangefinder. This needs to be very precise and requires precise manufacturing and occasional corrections.

Summicron M and R - there are many types designed by different designers across several decades with different technology available at that time. where construction is identical between R and M (1976R and 1979M) so is the performance and character.

Modern Zeiss Planar - RF version is an f/2 and SLR version is an f/1.4. Different designs, different performance, different character.