Cams.com from Friend Finder Networks has recently transitioned away from a straight per minute local currency based billing system. Users will now be able to purchase credits via a token based system when they want to access live adult webcam shows at Cams.com.
As far as the cost or value of tokens at Cams.com they are worth .10 cents each. This is a similar value that other cam sites have established for their virtual currency.
Currently most mainstream live webcam sites for adults use a tokens system as the currency of choice. This includes sites like Jasmin.com, Chaturbate, ImLive, CamPlace, Flirt4Free, and BongaCams.