The AH is now offline, so there's no way to check what crafting materials go for anymore. New ones are also Account bound, so you can't even trade them even if you wanted to.
It depends on what crafting material you are looking for. If you're looking for Subtle Essence and Fallen Tooth, your best bet is to farm as much gold as you can, and buy it from the auction house.
Currently, the crafting materials are selling for 20 and 45 gold, respectively. That is drastically cheaper than buying shop items, or even farming them yourself.
Source: this answer.
So, the answer fluctuates. In the event that the crafting material cost on the auction house rises above the cost of buying an equivalent magical item you can salvage, buy it from shops. In either case, gold find helps you.
For magic find, it will also depend on how long it takes you to find and gather magical items. The time investment will fall somewhere between the other two scenarios. It will take less time to find items you can salvage than it would to gather 1000 gold, but quite a bit longer than to gather just 25 or 100 gold.
The only time you want to really find magic items is when crafting material cost on the auction house goes above the cost of shop items. Which, at that point, becomes a stable economy for you on it's own. Buy magic items from shops, salvage, post crafting materials on auction house. Repeat. Use extra gold to buy items to salvage materials for yourself.
So, short answer, from least to most time investment, using Subtle Essence as an example:
- If: Crafting materials are dirt cheap (Costs less than you would get from selling magical items): Sell magic items and buy from auction house.
- If: Crafting materials are more expensive (more than selling your magic items) and less expensive than buying items from shops for salvage:
- If: Gathering requisite gold will take longer than finding magical items: Find magical items.
- Else Gather gold and buy from auction house.
- If: Crafting materials are more expense than buying magical items from shops: Buy items from shops, salvage materials, post on auction house for profit until price drops below viability.
Credit to LessPop_MoreFizz for the original information and inspiration.
Spirit Walk is a skill that fits into a category that I like to call "Panic Button". These skills can have other uses, but they're generally skills that are very good at getting you out of a bad place.
The Witch Doctor has a few other ones.
Horrify
This will pretty immediately clear the space around you of enemies. It will give you a few seconds to catch your breath and set up for the battle to continue. If you rune it for 100% bonus armor for 8 seconds, that will give you an additional boost for 4 seconds as the battle continues. Alternatively, you could rune it for move speed to help you get out of there as fast as possible.
Hex
If you are being chased by only one enemy, Hex will immediately chicken that enemy and allow you to catch your breath and get some bonus damage in. You can heal up and space yourself appropriately while he's a chicken so you can be ready when he comes back into his normal form. This particular tactic was the only way I was able to beat Izual on Hell difficulty solo. For some reason, Izual can be chickened, although I don't think any other bosses can. It's also particularly effective against rare monsters.
Grasp of the Dead
You need to either rune this for 80% slow or reduced cooldown for it to be particularly effective as a defensive ability. Both of these are solid choices, but the 80% slow against any enemy without the Fast affix is as good as just stopping them outright. This is very effective as a pre-emptive panic button. If you see a huge horde of enemies running at you, retreat to a choke point and cast Grasp of the Dead to prevent them from coming near you.
Fetish Army
The Fetish Ambush rune will get you out of a bind quite effectively. You spawn 6 fetishes, each dealing 250% weapon damage in an area when they spawn. This will usually kill everything in your immediate vicinity, and then you will have an army of meat shields to help you position yourself properly afterwards.
Spirit Vessel
This passive will save you from death once, but it really works best in conjunction with Spirit Walk. If you're using Horrify or Soul Harvest, however, this can definitely be a viable choice even without Spirit Walk.
Ultimately, however, Spirit Walk accomplishes multiple things at once, which none of these other spells do. Out of all of these options, none have the sheer utility of Spirit Walk. I recommend, if you insist on not using Spirit Walk, using at least two or more of these other abilities. I actually use Spirit Walk, Grasp of the Dead, and Hex most of the time for maximum survivability, and I still occasionally get cornered and have nothing to do but maximize my DPS before I die. Spirit walk is really, really good.
Best Answer
Probably just grind normal.
Consider the D3 Difficulty chart (click for full size):
Also at the bottom of this page
Since gear on your Barb at end game should be legendaries, and you don't get legendary bonus drop chance until Torment 1, your best bet is generally to clear Normal quickly until you can handle Torment 1. Actually, if you look even closer, the only bonuses you get from Normal up to Master are:
With this in mind, I would never run Hard. If you are interested in getting Blood Shards from Bounties, then Expert or Master might be worthwhile - as long as it doesn't take you twice as long to finish a run. The rest of the bonuses are nice, but generally not worth it until you get to Torment 1.