dont know how much money she had for each dvd she doing, may be she is rich ???
In case you really think that : maybe she is "rich", but it is not from the DVDs.
The general rule is : Gravure idols do not get a lot of money from DVDs. It is much smaller market than AV, there are a lots of girls in japan ready to do gravure...
And Anjuchan is rank 2 (some people even say high rank 3) gravure idol. None of her DVD end up in the yearly best sellers for years.
I have not seen Anjuchan in magazine covers too. And even with that a very big part of the benefits is for the agency...
Anjuchan will get money when people buy her checkis or the things she sells by herself, but even with that, she needs to make lots of side jobs to have a "good" life. For example Anjuchan was working in a maid Café in Osaka (if I remember it was the Charmy Moon).
But having done DVDs allowed Anjuchan to attract lonely men (that is how we call it here) and make them OK to pay a lot for goods she produces or as a hostess.
On a more contraversial topic, having done DVDs while being very young also make her have some specific people who follow and are ready to pay because of that. I think it would have been much more complicated for Anjuchan to start a career in Gravure if she had begun at 18 years old.
I would bet that Aichan has been making much more with her fantia, her "succubus role" / hostess, and things like that, even if she does not have as many followers than Anjuchan. Because it is self produced and all the money is for her.