Rather than going by cost per cap you should go by cost per mg of EPA/DHA (combined).

In this case the GNC has 180 caps x 300mg = 54,000mg. Price = RM69.93. Cost per mg = 0.1295 sen.
For the Pristin: 150 caps x 660mg = 99,000mg. Price = RM159. Cost per mg = 0.1606 sen.

So although the Pristin is more expensive, the difference is not as big as if you compared using cost per caps. Anyway, you sure each caps of Pristin has 396mg EPA, 264mg DHA?

I agree that molecularly distilled fish oil is a must to ensure no contaminants.

Yes you are right.  I calculated the cost for each cap and how many I would have to take each day and compared the cost.  I was actually looking for Watson's discounts for Pristin... but so far couldn't see any.  BTW, they don't have a proper website too, so couldn't find out much about them.