This makes a lot of sense, but it doesn't explain why the pricing isn't consistent. Why is an N1 the same price as an N2, except for sustained-use? Why is an E2 cheaper than an N1/N2D, except for sustained-use?

E2 is just such an amazing idea that feels like it's going to be under-utilized because it isn't cheaper for the sustained-use case. There doesn't seem to be any reason why E2 would be more expensive (to Google) for sustained-use and not for on-demand or committed.

Google Cloud is really nice, but the inconsistent pricing/discounting between the different types seems odd. Like, I'm running something on N1 right now with sustained-use because there's no incentive for me to switch to E2. It feels a bit wasteful since it doesn't get a lot of traffic and would be the perfect VM to steal resources from. However, I'd only get a discount if I did a 1-year commitment. For Google, I'm tying up resources you could put to better use. E2 instances are usually 30% cheaper which would give me a nice incentive to switch to them, but without the sustained-use discount, N2D and N1 instances become the same price. So, I end up tying up hardware that could be used more efficiently.