It’s so much easier to buy things in bulk most of the time. As long as you’ve got the storage available to you and you’re not buying something that’s particularly perishable, there’s no reason not to buy a bulk version of something. You’re generally going to wind up getting it for a better price.
When I was looking into getting some oil for my boat, I realized that I had the option of purchasing oil in bulk. This led me to go with a Mercury oil 55 gallon drum instead of smaller amounts of it. I’ve got plenty of room for storing it and I know that I’ll make use of it because I take the boat out quite often.