why not if somebody has too much space on his pc to fill it with more bots.. 20$ and you got a lvl 70 char which could farm ores/herbs for more income.
it doesnt matter if you bot 24/7 or not.. it?s just a bit higher risky to get reported by other players.. but no 1-60 would not get you profit quite much i would say 12$ the key and 20-22$ to sell maybe 10$ profit.
Trade your gold for a key and then it's really all just profit.
It's what I do. I used to just buy the X-Pack bundle from Blizzard and save like thirty dollars... Now, I've taken to trading gold for keys and saving all my money.