I banged out 94 mage last week using this method it was awesome. Ya i spent generally 80k-120k gp per 1k alchs (265k mage / 72k smithing).
I ended up with 77 smithing lol, I dont see it being to useful to me but, hey! 77 smith! lol
Also, people tend to say well thats 265mage exp per spell while alching is 325 or whatever per spell. The thing they don't realize is that alching takes like 3 seconds per spell, meanwhile superheat spell takes like half (closer to 2/3's) the time an alch takes so with that being said, superheating is without doubt worth using to train mage, it can just be annoying having to individually click each ore and repeatedly bank every inventory. Also for those who say iron ore is difficult to buy, not at all. I had a more difficult time selling bars. And you can actually end up making a decent amount of money if you take the time to sell because alot of people are looking for like 3-5 iron bars for quest items and they generally say things like "buying 5 iron bars 5k", so that's easy to take advantage of.