I'd rather play the 14 day trial. 1-20 doesn't take too long if you keep at it. It's so much easier to level up in WOW nowadays.
‘World of Warcraft’ is sort of free-to-play, if you’re into restrictions
If you wanted it to go on even longer, you had to pay $20 for a copy of the original game, which would include a 30-day trial period, as well. That helps, but you still have to shell out the cash.
Not anymore, thanks to the new WoW free-to-play system. You can play any kind of character (minus those added in Cataclysm) up to level 20…for free. For as long as it takes. Did you get your character to this “max”? Create another. If you’re fine with going from 1-20 over and over, this could be fun for you.
And if you decide that you’re willing to make the commitment, $19.99 gets you the original game as well as the Burning Crusade expansion in a “Digital Battle Chest.”
Unfortunately, something like this has a ton of limitations. I’ve included Blizzard’s full list here:
The following restrictions are placed on all Starter Edition Accounts:
– A level cap of 20.
– A maximum of 10 gold.
– Trade skills are capped at 100 ranks.
– Unable to trade via the Auction House, mailbox, or player-to-player.
– In-game access to public chat channels unavailable. Players are limited to communicating using only say, party, or whisper.
– Characters will be unable to create or join guilds.
– Characters are not able to send whispers to other characters unless they have been added to the characters’ friends lists or have received a whisper from a character first.
– Characters will not be able to invite other players into a party.
– Characters will not be able to join parties with other characters above level 20.
– Voice chat disabled on Starter Edition accounts.
– Realms experiencing login queues will prioritize players who have full, paid accounts.
– Starter Edition accounts are not eligible for character transfers
– RealID features are disabled on all Starter Edition Accounts.
For more information, check out the official FAQ.
I know of a few people who have said that they'd like that just to get a head start before officially paying for a subscription and buying the game. Also, if you're a really slow leveler (like me) it could take way longer than the original 14 days just to get that far.