My web skills are limited. I guess I thought my eyes were about as bad as they got :)
The $10 CarParts.com filter was a Motorcraft filter. Lately Wal*Mart has not carried the Motorcraft Filters . They now seem to carry only Fram filters for my old truck for around $10. Rock Auto has a range of filters for the old truck from $8.05 (Pro-Tec) to $31.99 (FRAM Air Hog). Amazon carries the correct Motorcraft filter for my old truck for $15.23. They also sell the K&N Filter for only $40.46 and the Care Kit for $8. Using these numbers, the K&N economics look a lot better. (5 x $15.23 = $75.15 for paper filters vs $48.46 for the K&N in 150,000 miles using my original assumptions about change intervals). Of course this still doesn't account for the pain of cleaning and re-oiling the K&N or the possibility of contaminating the MAF sensor.
It is my opinion that for the vast majority of people, using a K&N filter is not a smart decision. There are plenty of people who report remarkable gains in performance and unbelievable (and I really mean "unbelievable") gains in gas mileage. To each his own. I do know you'll never see one in my vehicles.
Ed