Personally I have no idea what are good offers for Aethers, even if I was still spending I doubt Aether offers would be high on my priority list. Without analyzing those they seem to be extremely overpriced for something not really needed…
Semi-solicited advice: Be patient. Use offers to complete stacks that you mainly fill through random rewards, rather that buy stuff and simply ignore the rewards as unimportant. Your heroes aren’t going anywhere.
