I bought 5M for one of my pures and when I was talking about it with my friend, he said if I were caught not only would my pure be banned but I would be unable to log on because of an IP ban. Now, obviously there are ways around this (Proxies), but does Jagex really do IP Bans?
It's really really rare that an account is banned by gold trading. Ppl but in amounts of 1000 millions and still don't get banned. So I guess that an IP ban would be extremely rare. Don't worry about 5m, its nothing compared to what others buy.