Would be less.
Some guy use 1k zeal to get from 88 to 99 strength.
It would be less xp meaning less zeal.
My guess would be around 700-800 zeal.
Goodluck.
Well 700-800 zeal approximately, which would take probably around a month. If i were you I would high alch during the day when you were on, then auto soul wars at night. It would make it much quicker unless your in absolutely no rush for 99 magic and don't want to spend any cash of your own on it.