Well be aware, 300mg of EPA means the value isn't quite as good as it may first appear. Multiply by 2.3 to get the dosage the same per $!
I have never used Swanson stuff before, typical worry about low cost fish oil is that it isn't filtered for heavy metals as well, and it may have a smell to it. Of course YMMV. :) I typically go to a local shop (more expensive of course!) and try out a brand there first, since I typically can return even the opened bottle if I feel something is wrong.
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)
http://www.swansonvitamins.com/swanson-efas-super-epa-fish-o...