My opinion, make of it what you will!
As it has the V5, it's probably legal ... still worth doing the HPI etc checks. It's about 12 years old, so will have long moved out of the "Dealer Servicing" regime. Realistically, you must judge the bike on its overall condition ... if it's clean and tidy (but not too shiny/tarted-up for sale

), starts and runs well, chain & sprockets, tyres, brake pads/disks are in good condition with some life left, fork legs still shiny/free from rust & bad pitting .....and so on.
If a Suzuki dealer is selling such an old bike, they're probably confident that it's OK ....I suspect they'd probably move a "dog" on very quickly, as they'd want to protect their reputation. Although it's always worth trying to get some sort of guarantee, even if only for a month!
Just my random thoughts....... Good luck finding the right bike for you!