Replying to a few posts earlier:
Yes Resolute Techniques is essential. This spec gets pretty much 0 extra accuracy % so even with 300 accuracy on every piece you can get it, you'll be well under 95% hit. I know that for me at 95 removing that talent leaves me with 77% chance to hit and drops me to 12k dps.
Elemental Adaptation as someone has already mentioned becomes amazing as you stack more +max res. If I was sitting at 75 all res I debate whether or not to take it but when I'm at 82 it's that much stronger and for 1 point it's a no brainer.
As for leveling and what to get, look I'm not going to spoon feed you guys. You have the spec, the gear, the way it works, everything really. You seriously don't need me to tell you what passives to get first especially since I've outlined how everything works and said to get BM/wrath/anger asap. It also hardly matters, it's up to you with what you prioritize in the passive tree. If you're HC you'll probably take the life nodes first, otherwise the deeps.
I think I lucked out a bit and only took about 100-150 chromatics to get my howl with the RRGB it needs. Spent around 300 though to get my 5L EV chest to RRRGG. I was at the point where I was just going to work with any next RRGGX that came up, was going to use Projectile Damage if green or added damage of some kind if blue but it came up RRRGG first.
In terms of cost for the setup I don't think it's too expensive. I camped trade chat for 2 days and ended up getting an Alpha's Howl for 2 exalt flat (was super happy about that) and my 5L chest for 5 chaos. Everything else is something I've found or something that I already had in inventory. I'm using a blue Fancy Foil of Fame (19% AS) because it's 2.02 APS. All of the skill gems are either cheap or given as quest rewards too. Most expensive part would probably be using chromatics and fusings to link weapon for leap slam and getting links + colours on chest and alpha's howl.