A Seemaster? Probably. A Seamaster, well it depends. If you mean the full size SMP model (also known as Seamaster 300) then quartz models still can be found below a grand, autos tend to be more unless rather tatty.
That isn't typical though for a full size model, regardless of movement. I would have snapped it up if I had seen one at that price.
I know of a 37mm one, automatic, in all steel and white dial for £825, and probably less with negotiation.