Hate to be argumentative but if you have regular oil, you should change every 5K or so (unless you drive a cab or severe service is normal). If you do a lot of highway miles, you can prob go more. With synthetic, going 15K with one filter change at 7,500 is normal. I've done this with every car and never had problems- taking three of them close to 200K miles before selling them with zero problems from current owners (friends) of those cars and no sludge, burning oil, and great gas mileage.
Changing oil at 3K miles is an unethical ploy by dealer service departments to make customers come in very often AND it is environmentally irresponsible as well. Even dealerships and oil companies are saying 5K or more with dino oil and 2-3 times as long with synthetic so don't be so quick to judge how this guy maintains his car. My Maxima had 243K miles and was still running fine when I traded it and back in the early 90s, I changed oil every 5K-6K with Castrol GTX regular. Sometimes I went 7k and when I traded it, the Honda dealer told me that my engine and tranny were in excellent shape though he simply had to wholesale such a high-mileage car.
I'm not defending anyone here- just pointing out that the 3K oil change is a bunch of crap that dealers and oil companies used to push to make more money.
It is a small sum of money and I would not care but another thing- I would not use "Subaru" filters. There are just a few that are really good and unless Subaru oil filters are made by the same Japanese company that makes Honda filters, I'm not using them. The new Amsoil, Wix, Baldwin, Mobil1, and Honda (Japanese version), Napa Gold, and the new K&N (not the old ones in 2003 or older) are the best ones tested and they seem to have consistent filtration and quality standards.