Condition really matters there.... from that age... if in "mint" condition, it would go for a whole lot. A real whole lot.
If it looks good, but the shutter maybe is burnt... a whole lot less.
Then there's viewfinder and lens clouding, viewfinder separation (common), fungus in the lenses (destroys the coatings then the glass), general wear tear scratches and dings. And, there's the ever present "vulcanite" coming off the outside (it gets very brittle and shrinks, splitting, coming off).
Condition is the key.... really, a proper appraisal is needed, by a reputable Leica expert (not some camera shop!)