Another way to look at it is to ask what the incremental cost of using better talent is.

If you're shooting an anal gonzo flick how much more does it cost to hire Kelly Wells instead of some newbie who thinks that "Enema" is the name of a rapper? How much money is really saved going barrel-bottom-fishing for performers?

In any case the crisis in porn isn't the performers but rather that near-total lack of directing talent. You've got companies trying to use their stockroom packing guys or their webmasters as directors, guys who feel a real sense of accomplishment at keeping the camera in-focus...

PS. I have always believed that the "shot out" phenomenon was less about the consumers being tired of a performer and more about studios having no choice since the directors can't do anything different.

Nearly all porn directors are at best one-trick ponies, shooting the same scene over and over, release after release, with the variation between "Blown Out Butts 37" and "Blown Out Butts 38" being the talent used - the director doesn't know how to shoot anything different, and so the performers must be changed to get any variation in the scenes beyond sofa color.