Some quick numbers:
- Steel wire rod seems to run around $500-$800/tonne, or $0.50-$0.80/kg:
A cheap road tyre is 365g in steel, 280g in aramid bead
MTB tyres seem to have a similar weight difference, though there are rubber differences also there.
I estimate therefore around 100g of steel reinforcement in the bike tyre, costing 5-8 cents. The aramid weighs around 1/6, of this so maybe 15g. At $25/kilo this comes to around 38 cents.
So the price difference should be 30 cents. I guess when you markup the price for sale you'd expect to multiply that by about 5, so maybe $1.50
If you consider the kind of garbage fitted to a cheap bike, then 'cheapest everything' and 30 cents off the price is 100% something they want. So we can immediately rule out ending steel wired tyre, because they are cheaper to make, they work fine, and many bikes are built on hundreds of such penny-pinching distinctions.
Well then why do they sell them at retail?
Because they want to get as much money out of you as they can. If someone is willing to pay $1000 (and they are) for a set of handlebars, why sell it for $100.
It's price discrimination, and it's there to get you too spend more. They make very little profit on the cheapest tyre, and more on each tyre as the price increases.
When Shimano sell the same brake lever with a screw blanked out as 'SLX' as Deore XT, that's not because it's cheaper to make, it's because if you want the nicer product then they will make you pay for it.
Given that getting a name as a bike tyre manufacturer is expensive in terms of large amounts of marketing, distribution, etc., there's literally no reason for them to sell 'nice' folding tyres for less money. I live in Indonesia, there's a local brand called Swallow, and there's also Schwalbe. Does it make sense for Swallow to add to their cost basis by using aramid? No. Because anyone who wants a nice tyre is buying Schwalbe or Continental. Is there any reason for Schwalbe or Continental to sell you a folding tyre for the price of a wired one? No, because people are willing to pay $50+ for a bicycle tyre, so they have no reason to engage in destructive business practices and eat into their profits.