It's Free-ish: World of Warcraft Classic is a free addition so long as you're already a paying World of Warcraft subscriber. If you've fallen off the wagon for a decade or so and want to give it a shot, you'll need to get back to paying the $15 a month.
However, the WOW Classic Gold in this game is very important, you need to consume a certain amount of WOW Classic Gold for every key action in the game. Now, MMOWTS is holding an event, any player can buy WOW Classic Gold at the lowest price. For more information please visit https://bit.ly/2NjPJhn