practical and fair in price

I think the game card prima. One needs no access to his account to authorize and easily control what you pay for the game. Application and activation work easily and quickly.
The argument of overpricing can entkräftigen. Because you share the price of the game card (€ 24.85) by 2 months, you get € 12.42, which is pretty much something between a one-month subscription (12,99) and a three-month Abonemment (€ 11.99 / month).
Whether this is for a computer game too expensive, one can argue about it, but you do not have to pay, too :) Otherwise remains a yes only the 6 Months Subscription by direct debit to save "right."