What does it cost to level Blacksmithing right now?

16.4kg in reagents at today's US auction prices, over about 98 crafts. Sell the results and it comes back to 16.4kg.

Where do these numbers come from?

The skill thresholds are read from the game client data for build 12.1.0.68914. The prices are the region-wide auction house, refreshed every few minutes; these are the snapshot taken at 16:57 UTC.

Why does the route change when I reload?

Because the prices did. The cheapest recipe for a stretch of skill is whichever one's reagents are cheapest at that moment, and that moves through the day.

Profession leveling · Cataclysm Blacksmithing · US · prices as of 16:57 UTC

Blacksmithing leveling 1 → 85 · Cataclysm Blacksmithing

16.4kg in reagents over about 98 crafts. Sell what you make and it comes back to 16.4kg.

Start skill

Trainer recipes only

Recipe names carry the colour the profession window gives them: orange is a point every craft, yellow is three in four, green is one in four.

Before the first craft — buy it all at once

One trip to the auction house. Vendor lines are cheaper from the profession vendor than from the board.

ReagentNeedEachTotal

Total16,377

Step 1 · Skill 1 → 3

Yellow

Folded Obsidium

About 3 crafts.213

per skill point106

Obsidium Bar×6

Step 2 · Skill 3 → 10

Yellow

Relic of the Past I

trainer

About 10 crafts.889

per skill point127

Obsidium Ore×50

Luminous Flux×10

Step 3 · Skill 10 → 75

Orange

Pyrium Shield Spike

needs the recipe item

About 65 crafts.9,340

per skill point143

Pyrium Bar×325

Step 4 · Skill 75 → 85

Orange→Green

Vicious Ornate Pyrium Shoulders

needs the recipe item

About 20 crafts.5,935

per skill point593

Elementium Bar×240

Skill 85 — done. Now sell what you made.

Crafted itemUnitsEachTotal

Folded Obsidium350

Vicious Ornate Pyrium Shoulders2047

209

Relic of the Past I101

1010

Pyrium Shield Spike0/650

0/650

Capped at what the market takes in 3 days, so a route never pretends to sell hundreds at once.

Back in your pocket16,376

What's worth crafting with Blacksmithing right now

Questions

How this route is built

What does it cost to level Blacksmithing right now?: 16.4kg in reagents at today's US auction prices, over about 98 crafts. Sell the results and it comes back to 16.4kg.
Where do these numbers come from?: The skill thresholds are read from the game client data for build 12.1.0.68914. The prices are the region-wide auction house, refreshed every few minutes; these are the snapshot taken at 16:57 UTC.
Why does the route change when I reload?: Because the prices did. The cheapest recipe for a stretch of skill is whichever one's reagents are cheapest at that moment, and that moves through the day.

A first craft pays Knowledge, not skill, so it is shown as a badge and left out of the craft count. Vendor reagents are priced at the lower of the vendor and the auction house.