To Tailor or not to TailorHi all, When I started WoW, I took the professions herbs-mining as I read on here that I could make most money out of them, but I got fed up with mining early on...
Fair market price of the mats + some arbitrary mark-up. If you're looking for common (trainer-taught or vendor-bought) enchants that sub-300 enchanters can do, then you're likely to get them at or below the prices of the mats since the enchanters really want to level their skill. If you see a lot of competing multi-line ads for enchanting in the trade channel, your odds are good.
For level 300 enchants and rare drops, the situation changes. The enchanters no longer are leveling their skill, they are thinking about the hundreds of gold they lost in the leveling process, they are probably lvl 60 and already rich, and can't be bothered to do "charitable" enchants. Now the mark-up gets steep, 1-50g, maybe 100g if that enchanter is the only known dude with the recipe. Good luck. :)
BTW, for mats required, you really need to print out a list from thottbot. Enchanters have a hard enough time fitting their available enchants into a multi-line Trade channel ad, and having to recite the required mats for a recipe to some anonymous whisper is a drag. Research the enchant you want beforehand, then check AH prices on the mats.