I thought this really came down to an "economies of scale" vs. "raw parts markup" tension.
Back in the day, a company like Sony could crank out CD transports for nothing because they built so many. Any bespoke audiophile brand that decided to make its own transport would incur dramatically higher costs to make something only marginally better, if better at all.
But if Sony had to put V-Caps in its CD players, well that's maybe $300 wholesale, mark it up for Sony's profit, distributors' profits, retailer's profits, you're probably looking at $2000 more on the sticker price. Not going to happen.
But if you take advantage of the scale of the $800 Sony player that Sony can make for nothing on a huge scale, then solder in some $600 retail V-Caps (or whatever other audiophile mods make sense), you've built a $1400 machine that would have sold for $2800 if Sony had to make it. Isn't that the economics? The trick is knowing where the shortcomings are that can benefit mods. Guys like Dan Wright built a career out of it.
If you hand built speaker cabinets to build some of Danny's great designs, that's going to cost you compared to the Columbian or Chinese factory that's cranking them out for a major speaker manufacturer. But if Danny can spot a good design, with a good cabinet, with decent drivers, that had to skimp on caps, or cabinet damping, or wiring, or resistors, or inductors (or whatever)... you could end up with speakers that compete with retail speakers at 2 or 3 times the cost.
BRING IT ON DANNY!
I'm dabbling with a similar issue now, getting some tuning done on a BMW 135i.