Level 83 and still can't complete an instance other than Blackrock

[Littleburst]

I really, really, really don't understand why everyone is screaming that healing costs so much mana.

I run protadin, disc priest, ele sham, destro lock, arcane mage And the only character that runs oom is my mage at times, because of chainspamming arcane blast.

It has to be said that the protadin has quite good gear now about 10 rare 308 pieces. But even when queueing with just my priest I hardly run oom. You just have to completely change the way you're healing. For a disc priest, only ever cast flash heal if there's no other option and greater heal might land to late. I even spam smite when i can for the 5 stacks = +15% healing and mana regain.

You have to check what spells costs and what they heal. The standard spammable spells have their costs increased indeed, but aslong as you can avoid those by casting every other spell when you can I don't really see a problem.

(my priest gear was mostly lvl 70 epics still, in full cata uncommons now(thanks to Auction house)

I'm with you on not managing other instances though. The new dungeons require A LOT more movement which is quite hard to manage. Beside that i personally still need to learn to heal. I spam smite 70% of the time which heals through Atonement. Messing around with Repeater Regions since yesterday.

[Tyval]

I had mana issues the first few times trying the first boss in throne of tides. Priest (disc) is my healer.

A couple things were the cause.

My team was taking too much dmg, so was going out of mana keep them all up. 1/2 way through the fight was out of mana, then of course everyone died . Solution to that was, concentrate more on avoiding dmg than doing dps.

Second thing as was mentioned above, Flash heal, I was casting this as my preferred heal. Since then I have stopped using it unless I need to, to keep someone from dying.

A third thing I got set up to do but haven't needed, is emergency healing with my shaman (they never run out of mana so figured a few chain heals might save the priest some mana, haven't really needed yet though).

Those two things made mana a non issue really. Haven't had mana issues since really. (granted there are more instances I have yet to try (only lvl 83)

The one other thing I did, which helped some I'm sure is I bought a few pieces of gear for my tank, I was in i232-i245 mostly on my tank, so bought greens at lvl 81/82 to fill out some spots that I hadn't filled with quests/random drops. Oh I also ran blackrock depths several times and got a few upgrades there. Boosted my HP a lot which made healing less of an OMG i'm about to die and more of a steady state thing.