One day I'm going to copy someone's high end blade profile and reshape my old low-end Wilsons to match, and see if it's profile or material that makes the difference.
I sort of did that once. I tried to copy an MK Dance rocker profile to a pair of Ultima Matrix Dance runners. It looked
easy to do. I didn't do a good enough job, partly because I tried to use an ordinary tool grinding wheel, rather than a purpose built skate sharpening tool. (Then I paid a pro shop to grind the hollow.) It's harder that it looks to do things exactly right. I also couldn't copy the toe pick, a major part of blade shape, because there was no metal in the appropriate places to copy it, and because I didn't have the right tools to do that right either. After trying them a bit, I threw the results away, wasting a $110 pair of previously good runners.
Bear in mind too, that if you remove too much metal, you remove the hardened part of the steel, as well as the chrome or nickel relief (the relatively soft metal plating that covers the harder steel, to prevent rust - which means your edge will not be durable - unless you are good enough to symmetrically remove the plating yourself where you need to).
And that copying the horizontal and/or vertical side honing, if the edges aren't parallel, as they aren't in Gold Seals, would require high precision machining, using expensive machine shop tools, that most of us don't have at home.
One thing really puzzles me - a few thousandths of an inch shape difference makes huge changes in the way a blade skates. OK, I get that the water layer on top of the ice, that the blade presumably hydroplanes over, is only something like 50 nm deep (about 2 millions of an inch). But a few thousandths of an inch is about the same range as edge raggedness. Why does it matter?
I corresponded at one point with a steel worker who wanted to make blades for himself. But he knew what he was doing with high temperature tempering and hardening, having done it professionally, and was used to working at and above the temperatures where those things are done. I don't know if he ever did it.
What it boils down to is that making your own blades well is beyond the abilities and equipment of your average home craftsman - so blade companies can charge a lot, regardless of what it costs them. Plus, figure skaters are used to paying a lot for skating equipment. Most of us wouldn't even consider buying $10 or $20 blade pairs, nor comparable price boots, even if they were really as good.
BTW, you can get blades that cheap - in fact a lot less - in quantity, wholesale from China, etc. In fact, you can get SKATE pairs WITH blades that cheap - comparable to many rental skates. That's probably where Reidell et al get their rental skates. (Which they resell to rinks in quantity for just very approximately $20 - $30 per pair, roughly comparable in quality to list price $40 retail skates.) But neither the shapes nor the materials are what reasonably advanced figure skaters want.
Now that hockey blade makers are raising their prices for the patented mount design blades ($40-$50 blade shapes now selling for up to $130), hockey skaters are getting used to paying more too, and maybe they can continue to go up to match us.
Since the pro shops make a cut of the final price, maybe the pro shops won't complain too much either.
Incidentally, if you look far back in history - e.g., before the end of the 19th century, there was a period when bolts and/or screws were used to mount runners. You can find pictures in old books. Which means the basic idea of replaceable bolt-mounted runners can't be patented, even if specifics can.