Here's my take. First, there is the cost of R&D, cost of mfg, and then overhead costs of just running the business. Obviously, no company is mass producing any of their cables once you get above $100 retail. The methods of construction can vary depending on everything involved. Yeah, some companies just have higher overhead costs, they look at the sales figures for each product line and then they determine what the market will bear for them to bring in so much profit to run the business and pay salaries, etc. etc. etc.
Originally, the first "EXPENSIVE" audio cables were first done by Monster since they used the MIT patented cable design which was VERY expensive to mfg, licensing costs, etc. That's when the whole concept of expensive audio cables first appeared. Then it's just gets more insane as time went on. Some companies are actually trying to lower the cost. Bertram pretty much went away with high markups and now goes either direct or through dealers that have lower markups. So, their prices have gone down by as much as 70% from what they used to be retail.
MIT has introduced their filter box cables where they went to surface mount technology and plastic cases for their "MORE AFFORADABLE" Style Series, but they STILL make their ultra high end models that cost in the $50K range, but they aren't selling these by the thousands, so they do have to at least break even in the end. And due to what's inside the boxes, the expense of the components (EXTREMELY tight tolerance), a LOT of hand labor (which isn't cheap), etc. they have to have enough profit to make it worthwhile keeping on the price list. Dealer markup is where a LOT of the price is at and dealers aren't swimming in money, since they have to pay for inventory, and they have to carry a decent amount, even if they only sell a couple of pairs a year.
Personally, there are way too many cable mfg on the market. Every time I turn around, a new one appears and some of these companies seem to just limp along. There are only a small handful that actually are doing well financially speaking.
I just wish there was a standard testing methodology where frequency response curves and impedance measurements were published to show us how different these cables are in terms of linearity and give us some indication on if the cable is going to match well, from an impedance perspective, to the equipment we are going to connect them with.
And in the audio industry, like many other, the retail prices go up on a log scale, but price doesn't necessarily mean better. So, one companies $100K cable doesn't mean it's going to sound better than another brand's $50K model, or another brand's $10K model. but within a brand, it probably will sound better because they are using the same type of technology, just on a level that just costs more. SO for instance, MIT's top end cables should theoretically sound better than their less expensive models because they are deploying more filters in those boxes, so the more filters, the more neutral the cable. But it doesn't necessarily mean that MIT's least expensive cable is going to sound worse than another brand's most expensive cable because another company isn't using the same technology.