As the potential seller here I'll be honest and say that GV (normal dates) aren't really that hot at the moment. That isn't to say they won't be at some point in the future and I'd say that the highest possible grades are not only the best to buy (they won't be making any more) for reasons previously covered, but they are also much easier to sell should you need to. It won't always mean a profit in 10+ years, but they will at least be easy to move on and if bought carefully I think in the event of a loss it will be very minimal.
Just buy what you like the look of and if you receive something that you are not comfortable with, send it back. Any half decent dealer will take things back without taking offence.