StarCraft2: pricing and subscription policy
Solution 1:
Starcraft 2 does indeed require a subscription... in Russia.
The pricing for Starcraft 2 changes from region to region and one of the differences between here and Moscow is that there you pay a subscription for Starcraft 2.
Its important to note that you can still buy a Full EU edition (in Russia) without a subscription and get along just fine. You are not forced to pay subscription.
Solution 2:
There are two (general) pricing options in Russia - either buy the full game (60$ "European" version) and play for an unlimited time, or buy a cheaper but time-limited version of the game. If you already bought the full version, there's no point buying any of the subscription-based versions, you don't lose anything - there's no extra bonus from the subscription, you're either able to play the game or you don't.
Notice the subscription is only about playing online - the single-player game isn't time-limited.
See more information here.