I'm not quite understanding the shorter oil changes means cheaper thereby less filtration oil filter. If large particles are in your oil, is there a certain mileage that they tend to show up? If you're talking sludge, then no argument, but if you're talking wear particles or intake introduced contaminants, then when exactly does an expensive filter versus a cheap filter come into play? If you buy a cheap oil filter should you then spend whatever it takes to get a fine filtration full flow air filter? Is it true that the longer an oil or air filter is in service the better it filters? Is it true that a new filter lets the most abrasives and contaminants pass because its pores/passages are largest at that point? I know filters reduce flow over service hours as they plug, but when is that truly a factor versus protection? If a filter is good for 15 microns and you have a bunch of 10 micron particles in the oil, what then? Is the filtration (both air and oil) just as or more important than the oil quality/brand? I'm aware that fresh oil has no entrained contaminants, but contaminants dont just appear at the 3,5,or7.5 k mark.
Another way to ask this question; "Would you mind if I dropped a small amount of silica into your fresh oil as long as it is smaller than what your inexpensive oil filter filters?"
Steve