I'm at VIP 2 and looking for diamonds and to level up without spending a bundle of cash. Which is better, the 30 day deal or Sackful of diamonds?
30 day deal is the best investment you can make here, buy it if you can constantly.
Sackful of diamonds is bad, I've only bought it once because first buy gives 2x diamond (and then, it still worse then 30 day deal).
Depends on how fast you want to level up and how many heros you have i guess and wether or not you have any double drops available so think about the speed you want to level up versus efficency of your resources
30day deal is best for leveling up. However, if you need diamonds quick, then a sack is the way to go.