From memory, the warrior package is 750 gems. I have not seen it come around very often. I bought one a few months back to go from high 70s to low 80s.
As with other game packages to get them offered to you, you need to be low on gems.
i.e. you are only offered packages to entice you to buy gems and not to just to spend them.
Not sure I understand the logic there perfectly but this is what I have seen to date.
Now, with the way skulls are calculated in wars right now, you should ask yourself if gaining levels quickly is worth it?
Since your defense (waves mostly, but also towers) will not increase, do the increased stats and the better gear offered by granny balance the extra skulls you will give your opponents? You might light up as the new weak link your team and lose tens of thousand of skulls. Before the wars, I would have bought as many warrior packages as possible. At this point, I would just pass. I actually flinched when I gained a level yesterday.
If you are as active in the game as you are in the forums, I have no doubt that you will level up very quickly.