Personally I would not fly just for earning miles. I'd probably be up for a detour or sth like that, but not booking a whole trip just for earning miles.
As you still have a lot of time I'd go with the 70% fare right now. That leaves you with 6K miles to earn over the next 11 months. Chances are that you will have to fly somewhere that you are not yet aware of right now, or if not, you can always later on decide if earning status is worth a quick trip on aegean or another carrier.
Two things to keep in mind: Status is not worth anything if you don't use it for flying, and secondly, getting 6K miles or 4 Aegean segments within Europe would/should be much less than 650 euro. Even business class round-trip on OS will get you 8K miles for much less than 650.