i have 75 magic atm how long will it take to get 96 and the price ?? (which spells too please)

thanks much

Really depends, a good way to train mage is safespotting at hill giant chamipions in the rimmington dungeon with the fire wave spell..

It really depends on your gameplay time, no one can tell you exactly how much time it will take :s

If you're worried about the price then I'd suggest training with low-cost spell, the Crumble Undead thingy <--Not sure of its the correct way to spell it. Use it on the Zombies.

You could also use (recommended) a Slayer Staff which will allow you to auto-attack that spell. The staff does not cost a lot, I could give you one if you want to

Good luck.

It depends on how much will you spend training it.
Spells I suggest; Crumble undead on zombies, Wave spells (fire, air, ...) on Giant Champions.
Price; it won't cost more than 15m for sure, but I can't tell you exactly how much.

Use Crumble undead on zombies cheap & pretty fast method.

if you have the coin for it just buy nats and high alch your way to it, 1.4k xp during double

If you are the lazy type [ like me  ] , follow this steps (but it require lvl 40 slayer and membership) :

1) Bring your fire wave spell , high alch spell runes , and fill the rest of the bag with food (doesn't matter what type) .
2) Go to varrock slayer dungeon,you can use wiki for the location .
3) once you enter the dungeon , you notice the Basilisk monsters area , the Basilisk are aggressive and attack you on sight .
4) Just stand on that area and make sure you tick the "auto retaliation" button .
5) Surf other websites , watch videos , do something else while your character is training .
6) Make sure to check every 2-3 minutes depends on your character's defend lvl and armor .
7) Basilisk also drops rune items , take them and high alch it for some cash along the way .   
 
EDIT : dont worry , Basilisk did not hit high and accurate , you will be hit rarely .

Basically there's a few ways to achieve your goal.

1. Kill monsters with high hitpoints and low defenses - these grant the fastest exp, it will cost the most money though since you require a lot of runes and the drops aren't really worthwhile - hill giants, moss giants, hill giant champions and fire giants are good examples
2. Kill monsters with a decent amount of hitpoints and higher defenses - these still grant decent exp but the drops will make sure you can pay for your runes or even make a profit - ice warriors, jellies, basilisks are good examples
3. Use monster specific spells like crumble undead - I have no idea how good this method is compared to the other ones but it's a fairly cheap one I've heard
4. Use the spell high level alchemy - this spell grants 738 experience per cast, which equals hitting a 9 in combat - this method grants a lot of quick experience and all you need are nature runes and a staff of fire - you can even alch trash items like fishing bait or feathers just for the experience, finding items to alch shouldn't be a problem

Thanks guys im going to alch when we get double xp

If you're looking to train two skills at once, smelting bars gives some decent exp too, especially during double xp.

Crumble undead or fire wave are both reliable methods.
You can alch just after casting either for an extra bit of exp, you'll need a large amount of items to alch though.