"So, how are their prices for videos, forms, posing guides, press credentials, etc?"
I've no idea what videos they offer, but I can't believe they would be a good investment. Forms? Most are available for free, just ask on this foruma and someone will have them or at least a source for them. Press credentials? Theirs will absolutely get you into event you could get into just by asking. Serious/major events issue their own specific press credentials folllowing a letter from a serious media organization. At a big time music event in Atlanta, I once saw a legitimate CNN on air/talking head type guy turned away because his name had accidently been left off of the list. He eventually got in, but only after an hour long wait while phone calls were made. Any event which will accept their press credentials is an event which you could get into simply by contacting the event publicity people.
Back when I was operating a commercial studio, I wrote out a letter for a model who was a major Elton John fan. The letterhead letter got her backstage and she was stopped only at his dressing room door. Their press credentials would not even have gotten her backstage.
Save your money!