Here are the results:
Enchanting takes the title for your most expensive profession to level followed by Blacksmithing and Engineering. I was surprised at the poor performance of Tailoring. The mats for the other professions are easily farmed but Embersilk cloth is a pain to farm even if you are a tailor. The drop rate for tailors is being increased so this I imagine is going to be less of a problem.
I think the poll is correct though, from 0-525 powerlevelling a profession enchanting would win or lose hands down.
Next poll will be up soon but I am thinking about a Trivia question everyday using one of the WoW calendars I recieved for christmas.