it all depends on what level you start at go to http:/www.tip.it/runescape/?page=firemaking_calc.htm and put in your current xp and it will tell you an exact number
You are looking at 131,378 Willow Logs.
It would take exactly 2555 willow logs.
1,187 - making willow short-bow's (u), may require less if you change to willow longbows (u) when you get to 40 fletching.
89,197.
You would need to chop 2793 willow logs from level 35 to level 60 woodcutting.
144, 679 willow logs, which equals to 2,025,506 GP if you want to buy them all.
You will need 150k willow logs to get 99 firemaking. I suggest using maples and yews after because it is faster.
Getting firemaking from level 60 to level 99 using willows will require about 134954 willow logs if using bonfires. It would cost you about 2.8m worth of willow logs or more if using the traditional firemaking method. Some money will be earned back with runes, firelighters and ashes from the fire spirits. It will take about three-four weeks if you play at least five hours a day.
43,479 As of 15th Sep 2012
1,021 Teak logs to get to 60 FiremakingFrom 60 Firemaking to 99, 63,016 Yew Logs.Note: this is the mid price optionThe most money saving is:122,551 Maple Logsor142,976 Willow logs, however this can still be dear.
You will need approximately 143,584 willow logs to get from level 53 to level 99 Firemaking.
That really depends on the type of logs. It also depends on your current level. I suggest you use a skill calculator - you can search for one online.