You can try the advanced search of eBay looking for sold vintage alarm watches. I don't think you will find this specific brand, but if you look for lesser-known brand names with plated cases, the prices should give you a general idea.
A forum community dedicated to watch owners and enthusiasts. Come join the discussion about watch collections, displays, watch winders, accessories, classifieds, and more! We welcome all manufacturers including Casio G-Shock, OMEGA, Rolex, Breitling, Rolex and Tudor, Seiko, Grand Seiko and others.