How long is it going to take you to recoup that $300 bucks? And don't most of them take a special cleaner and then need to be oiled? Add that to the cost also. For you - using the $75 a pop number - you would have to travel at least 200K before you even start to see a savings. Your at 53K on an 04 - so that's a bout 25K a year. So it's going to be maybe another 8 years before you recoup any savings on that $300 (plus cleaners and oil).
$75 I think is a high price to pay - I bought 2 filters last year - stock Ford Donaldson blue media - for $37.16. So I'm sure that if you look hard enough the deals are out there. Add to the fact that eventually the prices will come down.
So let's say you find them at $50 bucks - at your rate of travel and mileage on the filters that's six filters now and up to $300K and 12 years before you again start to break even.
As for the micron rating of the Donaldson - hell I can't remember - have it around here somewhere - but it's better than any other out there. Sure - the others may flow a tad better - but at the cost of filtration.
My views on it anyway
Ron