OEM costs would be my guess.

I knew a guy that ran hydraulic supply company. He sold to a lot of OEM's and all he cared about was price when it came to things like filters. They knew the customer was going to change them out anyway, so why spend a few extra dollars on something with no seen value?

I would sometimes go with him on service calls and I remarked that it was wise of him to sell his equipment with Hastings filters. He said everything I was looking at were replacement filters; he would never put something on his equipment with such a high cost.