Dont know about AD's in Germany or UK, but for a mint 2005 model with box papers etc, you are easily looking between Ģ3000 and Ģ3200 if not more. I am sure some one will correct me.
As for wanting a Sea Dweller, resistance is futile, I mentioned earlier I am on my 4th Rolex, once you start, you really cant stop regarldess of what opinions you have/had on Rolex.
some pictures to help you take the plunge....My ex-SD from 2008. Biggest. Regret. Ever.