I don't know man, if your pa-28-XXX is amortizing $12.5K/yr in maintenance, you're doing it wrong. Like putting expensive avionics on the thing, you don't really have to go carté blanche on the process. I purchased a warrior with a timed out engine and so far the mx cost has been much more moderated. I don't go telling the A&P to go crazy on the labor chasing every gremlin at 75 bucks/hr. I can see it shooting up to that mark if I treated it as a restoration project as opposed to the old 420nm shuttle I use it as.
My co-worker had a 12K bill after his first annual and the related belated mx.... on a fuel injected, CS prop, cessna funky retract, 177RG... and that was fully admitting he went carte blanche on preventive mx like hoses and such because he flies the family in it and feels uncomfortable with the bare bone mx he would otherwise be comfortable flying himself with. That's a complex retract and belated mx post-purchase. Even his second year of operation of said complex won't hit the 10K mx mark. But on a cherokee two years in a row? Yeah I'd be analyzing my expenditure patterns or getting rid of the thing.
I don't mean to discredit your experience, but I often hear these high figure maintenance costs on fixed prop trainers and attribute it to a more meticulous liberal spenditure attitude than the result of bona fide airworthiness-stopping maintenance costs. That truly is a personal choice for sure. Nothing wrong with that. But I find it a poor case to make to merely favor the RVs, and I'd love to chuck the slow-can for a 7A mind you. I'd love to justify sinking 65K unappropriated dollars I don't have on an aircraft much more capable and suited to my mission under the premise that it would save me the purchase price difference in year-to-year maintenance over a cheap timed out spam can, say for example my dream RV-6/7/A, but the fact remains that, at least for my ownership experience of both a C-150 and a PA-28-161, that simply hasn't come even close to being true. The opportunity cost is of course, not owning at all until I could afford the dream aircraft, but Im willing to accept that cost because I value flying TODAY in anything as more valuable than the prospect of flying tomorrow in anything.