I Guess I view it as saving 60% instead of $6.00
Plus I'm kind of OCD and I like to have supplies available so when a project comes due I can just go into the garage and have what I need instead of needing to make a trip to get it.
My stock of oil filters and diesel fuel filters, some of the various viscosities of oil for all my vehicles, and when I change the oil I top off the windshield washer fluid, antifreeze and check the brake fluid and power steering fluid.
Likewise a selection of windshield wipers, and Sprinklers that seem to get broken every winter somehow.
The kids put the spare cabin air filter for the lesbaru somewhere that I'm not sure where it is.