Great topic. Some folks don't want to hear the truth, but marketing is a huge reason so many speakers cost over 60k. Folks like to make big cabinets and there are people with plenty to spend, who want the biggest and the best. They feel that both walk side by side. Most of us who listen don't believe that. Too many of the 100k plus speakers just aren't as coherent or musical as many of their little brothers/or sisters IMHO. Many shop owners I've spoken with have said the same thing. The larger the cabinet, the more problems you incur. That's why so many feel the monitors are the best at getting out of the way of the mid bass on up.
As for R&D, of course that factors in, however the problem then occurs that if the R&D was a lot of wasted money, the price/value proposition may not be there either. Maybe it just took that long and so many iterations to get it right, but to what expense in the end? I have never liked (X brand) speakers (one of the most well known brands) for my tastes, but the owner and now his son are great marketers. Not saying they don't make a nice speaker, but I personally can't listen for long periods of time and yes, I've heard them at their best many times in many places from the the 250k-15K and all were run on the best amps the store sells. I had a lengthy conversation with a dealer that I've known and done business with since he opened in the 70's. We were talking about X brand and why they cost so much. He laughed and said that the replacement costs of all the drivers in their 50k speaker wouldn't cost the owner more than 1k to replace/repair. They have off the shelf tweeters that only use a slight mod and the other cones are poly and paper. Not the cheapest drivers, but not expensive and easy to get if you are a DIY'r. The cost is in the cabinets. The R&D and cabinets are the cost along with a ton of high end marketing. Even the cost to produce the cabinets isn't outrageous, but the demand is there and the cost is in line with demand.
This is just one example, however so many of the expensive speakers are priced that way, because too many folks feel that if it's that expensive, it must be great.
To get a top paint job, or a top veneer job is very expensive. We are going to pay for the cabinet and finish and the larger the speaker, but more costly. That doesn't make it a better sounding speaker though.
Most of the speakers I've heard in the high end of the spectrum are nice, but most aren't great by any means and they could be. Why do they sell us a speaker that has paper or poly cones at that price?
When I was looking for new speakers after many many years using various Proac's, I did some homework. Vandersteen was one speaker that wasn't on my radar as they looked generic and I didn't see why they were so expensive. I visited a local Proac dealer as I thought I'd just get their new D series speaker and be done with it. I hadn't liked most of the speakers I was hearing and I had auditioned well over 20 different brands (various models) and that also includes many of the 'garage' brands that sell from people's homes. There's a long story as to why Vandersteen, but the more I dug, the more I realized that his speakers were packed with not just R&D, but technology. His drivers are very expensive to make. The carbon ones specifically. He used room EQ for his bass and has built in subs. If integrated properly, I love built in subs with room eq. Cabinets inside a cabinet isn't cheap either and the finishes are as good as it gets, but I was able to chose nearly whatever veneer I wanted. Being a woodworker for fun, I love to play with veneer.
I think most of us on here really appreciate all of these things and are willing to pay for them IF the speakers sound great to our ears. There are a few top named companies who do spend a lot to make a pair of speakers, however I feel that way too many don't. Heck, most of us could build a pair of speakers that cost 25k off the shelf and with some reading and help, make them sound decent. To me there are some price points that make sense if you have the cash.
I've heard speakers at 14k that blow me away. A few have dedicated subs with eq and dig really deep and still keep a smaller footprint with a beautifully finished cabinet. At 30K things open up big time depending on your tastes, however I've heard too many speakers at the 14k-20k range that better many of the speakers that cost more.
at 50k-70k you can get some of the best sounding speakers you can possibly get. Any speaker will have compromises regardless of price. I just haven't heard big differences in sound from the 70k on up range than you can get at 50-70k. Vandersteen isn't the only brand I like either. There are others out there that are very nice and also use a lot of technology in their drivers as well as their cabinets. You don't always get what you pay for. Personally I just couldn't ever justify spending over 7k on a speaker that used paper and poly drivers or even off the shelf ones that use just a little modification.
As for the market, it's a strange one in that the more expensive gear is and has been where the money is. It does sell very well and is keeping many manufacturers in business. Many have had to go from the 5k and down range and open up the 5k- unlimited range in order to grown.