heres some more math for you bob:
as i already said, my truck sees "unaverage" service conditions. my filter requires service at more frequent intervals than what fords manual specifies (who the hell goes by mileage for an air filter anyway?).
your also about $10 high on your K&N cost.
but you forgot to add the cost of the K&N cleaning kit (if one so chooses to use one).
thats all been accounted for in my calculations.
you can disagree with my methods all you want...but the fact remains that a K&N is more cost effective for me (and many other people that operate their vehicles in extremely dusty conditions). and since you dont know me, my truck, or my preventative maintainence habbits, i can accuratly say that, in this case, you have no idea what your talking about