Dual Spec costs 50 gold at level 40

Dual Spec is in World of Warcraft: Forever from day one, but it is not cheap. At level 40 your class trainer sells a second talent tree for 50 gold, right when you also want your first mount.

Two builds, one switch

With a second spec you keep two separate talent builds and swap between them whenever you want. A tank and a damage build, or one for raids and one for PvP. A respec at the trainer costs more every time, so for anyone who changes often, the 50 gold pays for itself.

Mount or second spec first?

Apprentice Riding and Dual Spec together cost 150 gold at level 40. That is a lot this early, so many players will have to pick one first. It gets easier as you level: items sell for more, and quests give more gold from level 48.

Healers and tanks who level with a damage spec gain the most. The Shaman leveling guide, for example, adds Restoration as a second spec at level 40.