Skype group video has just come out of beta. It’s been free up until now so the details may still be a little fuzzy.
According to this page: http://www.skype.com/intl/en-us/features/allfeatures/group-video-calls/
* Trial group video is free for 7 days
* To get group video at home, you’ll need a Skype Premium subscription.
* To get group video across your business, you’ll need to set it up in Skype Manager.
What do you need? At least one person on the call needs Skype Premium or a group video subscription from Skype Manager. Two-way video calling is still free.
A day pass costs $4.99 / €3.49 / £2.99 for impromptu sessions while a monthly subscription can be had for $8.99 / €5.99 / £4.99 with a 33 percent discount available to anyone signing up for 3 or 12 month subscriptions over the next 30 days.