There is no actual gold cost for swapping around your specs or talents in the next World of Warcraft expansion. That’s gone. You want to be Shadow one minute and Discipline the next? Go for it. And there’s no gold cost for swapping your talents, either… as long as you’re in a rest area. That’s the game’s new compromise, allowing players to swap talents freely within designated safe zones but nowhere else.
Switching specs already has a large enough number of restrictions – having the appropriate artifact, the right gear, proper hotbars, and so forth – that putting a gold cost on top of it felt superfluous. By contrast, allowing players to simply swap talents anywhere at any time for no cost encouraged players to swap talents at a moment’s notice for a specific fight. There are plans to introduce a consumable item for Inscription so that players can respec in the field if necessary, but for the most part, you should expect to be sticking with your talent choices once you leave safety. Back in safe spaces, though, you can do whatever.
