I'm very willing to pay a premium for quality, I just can't seem to find any reliable signal for quality before buying. Price and brand are both increasingly meaningless signals.
I'm a value shopper. I was happy with the McDouble when it was under $1, but not now that it is nearly $2. It isn't worth that, but the BK Double Cheeseburger IS worth it even for $1 more than the McDouble (at least in my location).
Same is true for almost everything I buy. A certain fabric I want in my button ups, or a stich type I want in my pants. I hyper inspect almost every item of clothing I'm even contemplating buying. Same with furniture, with tools, with appliances.
It is almost a compulsion. I cannot pay more for something than I think it is worth... unless I REAALLLLLY want it.
For more niche stuff, Reddit groups like BIFL and seeing what niche hobby groups coalesce around is helpful for me. Which I suppose is the same reversion to word-of-mouth expertise when, as you said, brand and price are degraded signals.
Then there's two signals that negatively inform my trust of a brand:
- company size: the larger the company, the lower they start on my trust ladder;
- advertising: when a brand is overly present in the public sphere, that to me signals that they're overcharging for their product.