I don't usually count "content" in hours, but in quality.
Hunts, for instance, can take hours and hours, but that adds zero value to the game for me. (Of course it might add value for others)
About what can I buy with 10-15$.... well, If I'm not mistaken, a AAA game is usually released for about... 60? so 4-5 months shoud have the same content. But oh, wait. Those patches are not a new game. They add content, so... Shoud we compare the price with a new game? I don't think so. 90% of the graphic assets are the same (And that is what takes most of the money in the development).
An MMO can produce a lot of content per month. In fact they do.
The problem is that they are trying to catter all the audiences, so most people doesn't like most of the content. Of course that's the only way to get a lot of players...
Lately I think that the future of MMOs will come with smaller MMOs with less players and content more cattered to they're kind of audiences. FF XIV might be the last succesfull (At least to some degree) themepark that try to do it all.
But, please, here you are paying about 15$ / mothn plus about 30-40 each 2 years for the game or the expansions. That's about 200/year. I coud preorder 5 Fallout 4 right now with that. And I coud buy more than 10 Skyrims, wich is a more fair comparison, being all FF content done with more or less the same assets, with the same game engine....
There is not a lot of content.
That's why sucessfull MMOs are some kind of MIDAS for the companys. That's why SE went from almost being at bankruptcy to being in a pretty healthy situacion in a short period of time. Because they get an amazing profit with an MMO..... if it works well.
