How much does it cost?

Discounting R&D (i.e. prototypes, etc) & labour. Looking at materials cost + direct production labour cost...

TT (i.e. rockport etc, expensive): mechanical device, lots of engineering & precision machining, low production runs -> expensive.

Electronics (expensive): low -to medium cost. Tubes are hand assembled -> more expensive than ss that can be smd'd. Some tubes are rare -> cost goes up further. Chassis are expensive. Matching components requires time & large inventory-> extra cost. So it ranges b/ween 10%-20% of retail.

Spkrs: 10-20% of retail price

Digital: I can't say.

These are ballpark figures of course.

Dizzy -- as you note, SOny (for example) is playing in a different market, while hi-end is small & very fragmented & inelastic...

Retail (dealer) margin is another cost driver that must be factored in; in many cases this is 30-40% of total retail.

In other words, if you had the xover schematics & mechanical drawing for a pair of speakers, the diy version would set you back ~20% of quoted retail. The manufacturer should be looking at ~10% retail: a driver complement that sets you back $2k (that's a VERY expensive speaker!) should cost $~800 to the manufacturer, including "proprietary tweaks" i.e. touching up the drivers' electrical characteristics to simplify the xover).
Cheers

when you say that a driver complement cost 2000, wouldn't that equal to 200 to the manufacturer

If the drivers used are large production units (i.e. Scan, Vifa, Seas/excell, eminence, etc) there are substantial differences b/ween enterpise and retail purchasing ~1:2,5. When I refer to ~10% of retail, it's for the finished product (including cabinets & xover). This is especially the case as you go upmarket; a $40k speaker would cost you ~5k to diy.