It depends somewhat on where you sell it, and how you do it. That said I recently saw a similar revolver in slightly less condition go for $500.00 at an auction.
For the record I consider one made in the 1946 - 1960 era to be the best of the breed, excluding those made before World War Two. The Detective Special was based on a platform that was introduced in 1908. While an excelent one, it was dependent on expert hand fitting of the lockwork. As labor costs increased Colt was forced to cut back this kind of assembly, and pressure the assemblers to turn out more work in ever shorter time if they were to continue to be competitive in the marketplace. All of this is not to suggest that post-1960 guns were junk, which they were not; but as a rule of thumb they generally weren't equal to the earlier post-war guns.
I excluded the pre-war guns only because it is more difficult to find repair parts (especially mainsprings) and collectors have driven the cost of excellent or better condition guns out of sight.