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!)
Bleck, you are right, I shouldn't do math at the wrong time of day. :) The ones I am using right now is something from a company called SOLGAR (never used them before), 1 capsule is 504mg EPA, 378mg of DHA.
Still a fair bit pricer than the ones you picked out though, even ordering from Amazon ($20/bottle of 100)
(Also remember to take into consideration number of capsules in the bottle!)