I have several friends that also use the herring oil......we buy the 9 liter bottles and share the cost which breaks down to about $26 a liter .....which is much cheaper than purchasing just one bottle at a time. It stores well and can be kept for up to a year.
I have heard that it's not a good idea to buy liquid fish oil (as opposed to capsules) in large quantities because it goes rancid once it is opened, unless you can keep the air out of the jar........ I even read about someone who put marbles in the bottle to keep the air out!