$50, the same they charge Apps users. You can't buy support for @gmail.com accounts.

Forward your email to an Apps account, then set up your @gmail.com address as an alias. Works great and you get support. Gmail is smart enough to set the outbound email address properly for any replies.

I don't know, but I'd be willing to pay a fair bit per incident. I suspect it would be well in excess of what it would cost to provide such support.

I think that model creates a moral hazard considering that in this instance the account was locked down by Google.

Perhaps, but I don't think that's a reason for not using it. There needs to be some solution, it needs to be something you can implement after the fact, and it needs to be worthwhile for the company to provide. "$100 to talk to a human, refundable if we fail to solve your problem" is a model that would actually work.

Yup, it's perhaps a tough PR sell because it create the potential for misaligned incentives, but I don't think it is a totally crazy idea.

I'm pretty sure Microsoft waives the fee for their paid TechNet support if the problem was due to a legitimate bug or problem on their end.

Microsoft probably has a much higher ARPU than Google does.