I'm not sure what you're getting at. On my last two houses, I had to
replace the roofs that were on the houses when I bought them. I've never
had to replace a roof that I bought, but that's because I don't stay in
one place long enough.
In both cases, I replaced the damaged roofs with GAF 30/yr asphalt
shingles, which is what everyone else in those neighborhoods used and
what the HOA mandated. (Most of the houses in both of those
neighborhoods were getting new roofs as a result of a storm that passed
through.) I would expect to get 10-12 years from those 30/yr shingles,
but I wasn't there long enough to find out. What I do know, though, is
that the mfr's warranty is no match for hail and tornadoes. One of my
neighbors in San Antonio was mad because he had to replace his roof
twice in the same year, (two insurance deductibles), but mother nature
doesn't take that into consideration.
Where I live now, we haven't had a tornado and our hail has been
manageable, but we took a fairly direct hit from a hurricane last year
(115-125mph winds) and our then-two-year-old roof only lost a few
shingles, mostly up along the ridge vent. I talked to a couple of
roofing contractors at the time, although I ended up not using them, and
they said a typical asphalt roof gets replaced in 8-10 years here, so
that's the same as my last two locations.
Judging from your reply, you probably get a longer life from your roof
than we do in Kansas, Texas, and now MS. Or maybe you're not using
asphalt shingles. Composite, perhaps? Steel roof?
If you and micky are still using the same roof after 20 years, more
power to you. I've lived in over a dozen parts of the US and I don't
think I've ever seen that except from a steel roof. We're not allowed to
use those, but I wouldn't anyway because I wouldn't get the money back
when I sell.