The Watson Monorail Camera is a large-format view camera built on a monorail design, the configuration favoured for studio and architectural work where extensive movements are required. Sales records for this model are scarce, and detailed factory documentation is not readily available.

Auction evidence is limited to a single UK saleroom result of £276 in 2017, a hammer price that reflects wholesale auction levels rather than retail. With only one data point, it is difficult to say with confidence what a Watson Monorail Camera is worth or sells for in today's market, and any current value should be treated as indicative only.