The Leitz M Prototype (24x24) is a 35mm rangefinder body built around an experimental square 24×24mm frame format rather than the standard 24×36mm full frame used on production M cameras. It is a one-off or very-limited factory development piece rather than a catalogue model, which places it firmly in the collector-prototype category.

Sales evidence is extremely thin: a single recorded UK auction hammer result of £3,000 from 2009 stands as the only reference point, so any sense of what this prototype is worth today rests on that lone wholesale data point rather than a true range. Because saleroom appearances are so rare, the price a fresh example sells for in 2026 would be driven far more by provenance, documentation and bidder competition on the day than by any established median value.