Well, if you don't pay the fee you can't play. It's that simple.
World of Warcraft has a monthly subscription, regardless of which expansions you have installed. The expansions do cost money, but once installed you don't have to pay extra - the subscription remains the same.
The game installer can be downloaded freely from the world of warcraft website. You will still have to pay the monthly subscription fee. There is no way of getting around this.
The subscription price per month for World of Warcraft is $15.00 each month. There are discounts if you pay several months ahead.
There is no way to legally play World of Warcraft on a Blizzard server without paying the subscription fee. Note that it is also possible to extend your playtime using Game Cards instead of using a credit card.
You cannot play world of warcraft on any official server if you do not pay subscription fees, but there are private servers where people play. These are not endorsed by Blizzard and very buggy, but usually free.
When your friend pays for a 1 month subscription for World of Warcraft
You go to your battle.net account, and log in. Click on your World of Warcraft account and check the subscription details. It should tell you how much game time you have, and when your subscription is due to be renewed.
Warcraft 2's expansion, Both Warcraft 3's and World of Warcraft are all online play. warcraft 2 and 3 use battle.net, while World of Warcraft is a paid subscription MMORPG
$14.99 per month but you save some money if you pay for 6 months of subscription at a time.
You have to buy the game. Then you have to go to the official World of Warcraft website (listed below in the related links) to start a World of Warcraft subscription.
You can get time cards or a monthly subscription
Yes, if you buy the installation Cd's/dvd's you still have to pay the monthly subscription fees. There is no way around this.