I have been extremely lucky finding good deals for filters on fleabay aka eBay. I’ve gotten oil, fuel, coolant filters as well as coolant test strips, coolant and coolant flush, etc. this week I got the Fleetguard oil filter for well under $20. It just takes some searching. The filter I bought for under $50 retails for over $120 at my local Cummins dealer.
2000 Country Coach Intrigue "The Beast"
40 ft Cooks Delight - 350HP ISC Cummins