Ten years' durability* for non-underwear garments is what I shoot for as well. It's possible to get considerably more than that with a little extra care [for example, line drying rather than putting in the dryer machine]
-- I've pretty much always dressed the same -- it is more difficult to find quality clothes these days, even from mail-order places that used to be reliable in that regard.
What I look for is :
- practicality
- durable + comfortable fabric
- quality fittings e.g., zippers / snaps
- solid workmanship
- thrifty price for value
- where it's a reasonable option, I go for stuff made in the USA
Since certain makes of clothing are already under discussion here, I'll add a few of my go-tos -- n.b. I have zero affiliation with these or any clothing companies:
~ Flannel shirts : Codet / Big Bill
~Rugby shirts and similar : Columbiaknit
~T-shirts, turtlenecks, sweatshirts : Union Shirt Supply
~Jeans : Roundhouse, Texas Jeans
~Khakis : Bill's
~Polyester "dress jeans" [? right] : Wrangler 'wrancher'
[made in Mexico, last forever]
~Cycling bibs : TheBlackBibs [great, made overseas]
~Mountain bike shorts : Zoic [reasonably OK, made overseas]
~Dress shirts : WhiteDressShirts [when absolutely necessary]
~Belts : Bison Designs
Socks and underwear - there used to be good options in this category, but getting verrrrrry hard to find, so I've regrettably started treating them as one-or-two-season-then-toss
- When I can find the time [rarely], I also look for stuff at thrift stores, mainly for the environmental benefit [though the low price doesn't hurt!] -- mostly oxford shirts for everyday wear
I have a hard time focusing if I'm not comfortable, so for me, clothing like the above is a worthwhile investment
*I used to get this much wear and more out of shoes [buy quality boots and shoes, get resoled as needed], but since I've moved to sneakers [due to leg and foot injury], generally I only get a season out of sneaks even with a multi-pair rotation.