Like I've said before, it all comes down to an individual's comfort level. (And a lot of times, we ask questions looking for an answer which matches what we've already decided.)
I'm in the leave-it-in camp, & agree 100% with Spector, satterfi, Al & Dr T. Use a quality oil & leave it there. Any quality oil should have enough TBN for a year, but if it's creating worry, simply switch to something like Saab's OE 5W-30 semi-syn ($2.99/qt?) with its huge TBN reserve. (That stuff will probably go for 2yrs on that TBN!)
My comfort level is now bordering on Caribbean/Jamaican for my oil changes. (Ya man, don'cha worry 'bout no bad ju-ju setlin' down'n dat basin, bra'...) In eight months I've put about 2700 miles on my 4qts, & it's not coming out until I reach 10k.
And while I agree that UOAs are expensive, keep in mind that they're a tool. A lot of people take a used car & pay a mechanic to look it over before buying it. If the mechanic finds nastiness & you don't buy the car, is that $50-$100 wasted?
You don't have to analyze every 3mos; do it when you change the oil. Then decided how long the next batch can stay in & test it again when that oil comes out. Once you establish how your car treats the oil, you can make an informed decision about change intervals without guessing or worrying about it. And when you have that info, you can then decide if continued UOAs are necessary, or if you're happy with what you've got.