Damn, that would cost a shit load.
When I got 99 range from around 85 back in early 2011, it cost me about 60M on prayer pots and chins alone. As I haven't really watched the market, I would speculate it to cost around 200M+ if you bought chins, prayer pots, and the cannon balls.
But I suggest Ape Atoll over Chaos Tunnel Skeletons. Way better xp at Ape Atoll.