worried about pvp in regard to mana

I'm a little nervous about pvp and I understand that it is a little preemptive but I would sincerely appreciate community thought on the matter.

Mana mana mana. Spell steal for example costs 5k. You can spam this 10 times total and you're done. Other spells cost too much as well, I get burned out quickly and I'm not hitting any harder than a melee class. Death knights for example seem a lot better to play. They do not require mana, do overall the same damage and so far have more health.

Honestly, its fine the way mages play if they are going to hit a lot harder than melee and burn out fast. But my experience so far is they are hitting about the same as melee and non mana based classes.

Just sayin :P