Personally I never go over 150ph for anyone - and that has to include anal or I won't go over 120.
And any time I've read a review of one of these so-called porn stars, it's always sounded negative (even those rated postive or neutral), with comments about them basically treating you like you should be honoured to be allowed in the same room as them, basically thinking they're something special when they're really just another hooker. Just because they went through the motion, doesn't make it a positive in my view, it's all about the actual service.
So no - in my opinion they aren't worth it. Nobody is.