Do you wish to train your magic quickly or do you wish to train it economically?
I spend 10m from 81-94 magic ice bursting monkeys in ape atoll. However, I was getting 200-300k xp per hour and I was semi-afking (I had to click a prayer potion every 3 minutes).
I hate alching. You get a max of 100k xp/hour, spend 2gp/xp and have to click non-stop.