100k loss per 1k alchs is way too much man. I alched the majority of the way to 99 magic (after 95 I bursted to 99), and on average I would lose anywhere from 5-20gp per item depending on what that item was. But the loss was anywhere from 5-20k per 1000 alchs, which adds up to only be a couple mil at most once you hit 94+. If your losing 100k per 1k alchs I would definitely find some different items that you can alch to avoid losing too much money. Alching is supposed to be a cheap alternative to training your magic