"I'm not sure why they're using the same price model as Amazing Muscle Beauties, which is an established site with a large amount of material and regular updates."
My guess is that her website is owned by the same guy/photographer as Amazing Muscle Beauties. The sites look very similar & he uses that same kind of 3 month pricing. I once wrote him right after he started his site asking him to consider a $30 a month subscription & he told me that, if he did, some ppl would just grab everything on his site ever so often & then cancel. I can understand that somewhat but it's still annoying if you're on a limited budget like I am.