Specifically, why is this one $48 while this one is $7? I realize they're not exactly the same (but very similar), but is one 7x better than the other, or do they just know that we need very specific ones for our frames?

one is machined billet aluminum, the other is stamped cheap junk aluminum...

the wheels mfg. part is better quality, and stronger... but is WAY overpriced... look for it on EBAY... about $20, shipped.

The better question is, why are there like 200+ different ones? Even in the "our only standard is no standard" cycling industry, there's usually a limited number of something-- there are what, 15 seatpost diameters and a dozen different bottom brackets? But I've seen derailleur hangers that fit ONE bike.

And if you have an older bike that was not one of the really popular ones they are impossible to find.

It is $48 'because they can". Manufacturing costs and material costs would not vary more than a few dollars from the $7 hanger. Hangers should
be soft non-alloyed and non heat treated aluminum. They are designed to fail first, preserving if possible the RD, but especially the frame.
The $48 one may be for a limited production frame.

I don't know why that particular Wheels Mfg hanger is so expensive, especially when the Wheels Mfg page linked above notes that the particular part (DROPOUT-8) is the "same hanger as our DROPOUT-6", which is priced at $22. Same hanger but 1/4 the cost? (And DROPOUT-6 is $16.53 via Amazon.)

Also, when looking at prices on the Wheels Mfg web site, keep in mind that buying directly from manufacturers is often more expensive than buying through their authorized resellers because the manufacturer doesn't want to undercut their resellers.

Cos the bike industry is dumb, your always going to have a few standards (due to material properties), but as is, there are hundreds, for everything (see the Wheels Manufacturing BB chart to get an idea), there seems to be a great reluctance to stop making one thing when another comes along, 1" headsets were kept for several years after 1 1/8" was standard (looking at you Trek in 1996).

Things like MTB's with 29er then 27.5 wheels, the 26" market was declining, so lets make a new spec, so everyone has to buy kit all over again, it may be a little better, but is the cost worth it?

that $7 one is cheap ALLOYED aluminum... stamped out in a hurry, and poorly finished... the other one is higher grade billet CNC machined alloy aluminum that is then hard anodized for strength.... and won't bend in a light breeze like the cheap one WILL.

the billet one is the one to have... they can be straightened a couple times before they crack... the cheap ones bust first time, or get cracks in them if straightened a bit, usually..

and ALL aluminum is alloyed... the pure stuff is nearly useless.

Yup, shoot, my Paragon Machine Works slider dropouts are only $13 each+ shipping. Those critters will bend like hell, and the threads will rip out before the hanger snaps off.

Guys...

Dropout hangers are SUPPOSED to bend.

That's the point.

Yes, but they still have to be a bit stronger than butter to maintain alignment against the stresses they endure in regular use. I've seen some that would not.

You are exactly right. As a life long technician, non standard parts of the same function really should have been standard, drove me nuts.