It all depends on what method of training you'll be using. I've added a related link to a magic training guide. This guide suggests fire strike, fire bolt or high alchemy for f2p and level 6 enchant, high alchemy and mage training area.
For these spell you'll need the following runes:
Fire strike 3 Fire 2 Air 1 Mind
Fire bolt 4 Fire 3 Air 1 Chaos
High alchemy 1 Nature 5 Fire
Lvl-6 Enchant 20 Earth 20 Fire 1 Cosmic
You can also go to Fist of Guthix, to use free magic runes.
lvl 70 wc buy a ton of runes
99 strenght cuz all u need to buy is food and armour and weapon, with mage, u have to buy all three and also runes which cost a lot.
Look up a magic calculator, then how many times you have to plank-make from 86-99 magic, then add the prices of the planks + runes to cast the spell together, to get the cost.
To get 99 mage fast is to high lvl alch from lvl 55-99. i dont have 99 mage but i heard u need about 19k of nature runes. (if i am wrong correct me) and a fire or lava staff.
well 1rst go to a fist of guthix world then play fist of guthix well then you have to bring your best magic stuff you wont need runes because whenn you start the game they will give 3000 runes about(this will only last util the game is over or you lose or win) well i got lvl 99 magic like that subided by zezima
about 70-100 days when you have got the level for nature runes
you'll need roughly 3511 nature runes if ur gunna cast high alch to get to 99
Deaths runes Law runes nature runes all make you decent profit but i recomend nature runes as they are a good souce of money and xp, 1-99 runecrafting takes about 4months if u no life it or it can take 1 year if u play for about 1 hour a day lol hope this helped :)
Same as for level 99 in any other skill. About 13 millions.
Years.
the best thing to do to get 99 is this and it has profit get like 5k mind runes and air staff and do that untill ur high enough to use chao runes then get enough chaos rune and train till lvl 45 now the easy part do from 45-55 camelot telle for 55.5 xp per cast and after 55 high alch maple long bow (u) before 45 its boring and stuff but this is best way to get 99 if your member f2p i dunno
I'm 99 wc and I like to chop magic trees, I make around 140k per hr.