If you're saying there are equivalent shirts today that are as good but just in different styles and materials, I don't think there are, not at the inflation-adjusted ~$18. $50, and maybe you're getting somewhere. Maybe.
I do get that the specific type I called out might have some functional equivalent that's simply a different style & material but is just as good, but not that cheap, they don't. Under $150, probably, sure. Under $50? No.
This suggests that the cost of clothing has inflated at more like 3x the nominal inflation rate, despite the existence of $18 (or cheaper!) shirts—the inflation was eaten up by worsening quality, rather than showing up in prices, but like for like, even with a generous "functional equivalent" accounting, the change was more like $0.79 -> $50+ than $0.79 -> ~$18—your "equivalent" dollar under the latter calculation in-fact buys less.
You are talking about the hedonic adjustments which is a hugely studied part of inflation calculations. For any way to calculate broad inflation you’ll find products that inflated more than the calculation (and less).
Your own example is an interesting one because a) it’s very hard to compare clothing by objective quality b) you’re changing the goal posts. I’ve found a carhart product that nearly exactly matches your specification and msrp’s for $40. I’ve seen discounters selling it for $25. Which is getting very close to your specific target.
I'm curious what other things when compared for quality would have a higher than 'normal' inflation. Perhaps we've been suffering a higher inflation across many 'dimensions'. If CPI doesn't control for enshitification, we technically have more inflation than we believe
I do get that the specific type I called out might have some functional equivalent that's simply a different style & material but is just as good, but not that cheap, they don't. Under $150, probably, sure. Under $50? No.
This suggests that the cost of clothing has inflated at more like 3x the nominal inflation rate, despite the existence of $18 (or cheaper!) shirts—the inflation was eaten up by worsening quality, rather than showing up in prices, but like for like, even with a generous "functional equivalent" accounting, the change was more like $0.79 -> $50+ than $0.79 -> ~$18—your "equivalent" dollar under the latter calculation in-fact buys less.