Well, you need 25,900 alches from 70 to 82.
The nats themselves will cost 6,993,000 gp. (270 ea)
Alching yew longs (estimate 600gp each)
25,900 of them will cost 15,540,000 gp.
That will be 22,533,000 gp
But wait! When you are done alching you will have gotten 19,891,200 gp due to 768 per alch.
Therefore 22,533,000 - 19,891,200 = 2,641,800 gp
The final answer is - 2,64 mill
- Bendik