What does it cost to level Engineering right now?

29.4kg in reagents at today's TW auction prices, over about 94 crafts. Sell the results and it comes back to 29.2kg.

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 19:54 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 · Northrend Engineering · TW · prices as of 19:54 UTC

Engineering leveling 1 → 75 · Northrend Engineering

29.4kg in reagents over about 94 crafts. Sell what you make and it comes back to 29.2kg.

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

Volatile Blasting Trigger×7631

Total29,397

Step 1 · Skill 1 → 60

Orange→Green

Global Thermal Sapper Charge

trainer

About 76 crafts.6,151

per skill point104

Saronite Bar×76

Volatile Blasting Trigger×76

Step 2 · Skill 60 → 67

Yellow

Heartseeker Scope

trainer

About 10 crafts.6,894

per skill point984

Saronite Bar×100

Twilight Opal×20

Step 3 · Skill 67 → 75

Orange

Wormhole Generator: Northrend

trainer

About 8 crafts.16,350

per skill point2,043

Skill 75 — done. Now sell what you made.

Crafted itemUnitsEachTotal

Global Thermal Sapper Charge38050

Wormhole Generator: Northrend850

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

Back in your pocket29,178

What's worth crafting with Engineering right now

Questions

How this route is built

What does it cost to level Engineering right now?: 29.4kg in reagents at today's TW auction prices, over about 94 crafts. Sell the results and it comes back to 29.2kg.
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 19:54 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.