I see some similarity with SBDX003 and SBDX001, whereby the former is limited to 500 pcs and with some gold trimmings on the dial. Saw some SDBX003 posted for sale recently at between USD3.9k-4.3k and a new SBDX001 goes for USD2k. Same goes for the SBDX005 and SBDX011 comparison.
Guess if the SBDB008 is kept pristine for a good 10 years it'll command a premium to the SBDB009. Having said that, I think SBDB009 is great for those (tool watch purists) who abhors the golden bits as being too flashy, and it is a great piece of design updated with the SD movement. If this is your first tuna, I would say go for the SBDB009 and no need to buy preown. Think of the SBDB009 as a modern successor to the SBDX011