This was brought to my attention by a customer so we bought one to check.
The cheap SCART to SCARTs on Amazon are not shielded coax, but paired cables.
Paired cable is somewhat better than non coax, but not by much.
The difference relates to the fact that the paired cable has an isolated ground wire (coated in transparent vinyl) running alongside each signal line whereas true shielded coax will have some kind of shield all around the signal line (in cheap VGAs for example, foil shield is used, in our coax cables there is copper wire wrapped around every core.)
The upshot of this is a cable that looks identical on the outside, and even very similar on the inside. It is however, much easier to solder paired cable because you do not have to strip, pull away the shield and isolate it in heatshrink. So you can produce what looks like high quality cabling with much lower production times, and the production times will actually be the reason for the low prices. That and it's probably new old stock that a European company realized they could get rid of in the USA.
We will never use paired cable in place of shielded coax. I thought this needed an update because the price per foot of Amazon scarts actually drops lower than our coax cabling supplier - but no, we are not going to use it in our cabling. It may well be slightly better than non coax but it's not even viable as an option there as it's way too thick.