Did i miss summer discount gold sale? Or has there been any?
there was a like a 50% off if you purchased 2 or more premium squad, and a cuople of months ago the put the 3 moths premium at 50% off.
nothing else relevant
damn i totally missed that 
Usually this type of sale start during the big summer and winter event, so soon™
i hope so.
Anyway, bundles and premium items may go on sale, but afaik gold itself is never discounted.
They discount it they add a little more gold to purchase up the 10€ 