Hi! Why don't you try a WTB for the watches you want?
You might get a well used seamaster auto for £750 but the speedmaster pro rarely comes up for sale below £1000.
You mention adding a nice watch to your collection, what other watches do you own? could you sell any of them to afford one of the above Omegas? or just keep saving, the watch will mean much more if you save hard.
Cheers Mick