How Long will it take to get 99 fletching and how much from level 70 on Runescape?

I'm at 81 I was going for 99 before I quit RuneScape, it all depends are how long you do it for and how focused you stay, one of my friends went from 61-99 in a week because that's all he did and he had the money for it(He did yew/magic longbows). For price I can't exactly say he was losing 1-2m a days doing it how he was.