Cheapest DPS profession to skill up?

[Giev]

Inscription is fastets/cheapest by far IMO. Apart from first levels (50-100 ish), you can easily buy loads of Ink of Dreams(cheap), stand next to ink trader and level up all the way to 600.

[Deleted]

Inscript is cheap indeed, however, i recently lvled Alch and im confident its cheaper to lvl and less potchy than inscrib.

[Deleted]

Inscription by far cheapest profession to lvl. You most likely need around 2k for plants (+/- 1k) to lvl it. If you check right glyphs and sell them on AH you propably end up making profit. I actually made around 3k profit when i lvled it.

Another easy one is tailoring, only northrend cloths may bring slight problems. If you farm these yourself you will lvl very cheaply.
And also alchemy (another alt was around 3k to lvl to 600) is piss easy.

[Skarssen]

Server dependent question, but I'd say the following, from cheapest to most expensive (without farming)

1 - inscription
2 - tailoring
3 - jewelcrafting
4 - alchemy
5 - engineering
6 - leatherworking
7 - enchanting (this can be lower if you level a crafting profession along side it, or haven't done much questing)
8 - blacksmithing. The range between fel iron bars and saronite bars can be more expensive than 1-600 in other professions.

[Clampz]

Windwool - Sneeze in Pandaria.

i spat my tea when i read this

[Clampz]

Next patch Blacksmithing will be cheaper than all others, as you can get from 1-600 using just Ghost Iron.

Might be worth holding out and getting that if you want a Blacksmith, the two extra gem slots are very good.

I have to disagree, because of the sheer amount of Ghost Iron that's needed. Have you looked at the numbers?