The bottle I mentioned is 700mg per capsule, the one you linked to is 300mg per capsule. Price per capsule is therefor not a good measure, you need price per mg instead. :)
(Also remember to take into consideration number of capsules in the bottle!)
(Also remember to take into consideration number of capsules in the bottle!)
Still a fair bit pricer than the ones you picked out though, even ordering from Amazon ($20/bottle of 100)