The problem is not that alternatives are too expensive, but that there are no good alternatives. I would be glad to pay $5/month to Google to get an ad-free version.
In my personal experience, it's been excellent. I've but using it for about a year and a half now, receiving from custom domains and sending from their servers.
Their webapp is better than Google's and it's actually the main reason why I've stayed with them.
It's also cheaper than $5/mo.
They are. At least the NSA is doing it at a global scale —thanks Mr Snowden for turning this "conspiracy theory" into an established fact.
> There is nothing interesting about an average person
Until there is. At that point, all they have to do is a nice search query into their ludicrously deep archive, so they can dig up whatever wasn't exactly average about that particular person. There has to be a trigger of course, but if you set one off, you'll be put on a watch list for higher scrutiny —at best.
Reputation perception by opaque large SMTP operators will not show up in RBLs and other ways to check for blacklists. You cannot query your IP block's status unless you happen to personally know a senior sysadmin on their mail operations teams. They don't share this information because it would help spammers choose new "clean" places to spam from.
One solution is to Colo your own 1u system with an ISP that is known to have very stringent zero tolerance abuse policies. Typically not one that is a commodity hoster.