The Joseph Audio speakers are comparable because they use the same woofers? Frankly, the Revel F208 at $4K/pair (net price) from B&M dealers seems like a better mainstream B&M alternative comparison with the Salks than the ultra-high-end JAs.
Yes, the driver complement is very similar, with the Salk having the more expensive tweeter, although not necessarily the better one, but that's beside the point. The guy with the most experience in design will get the job done cheapest. As in all things incompetence will drive up the cost. Lets assume they both have similar competence, then it comes down to the cost and standard of the boxes, freight and mark up.
I have seen Salk's work and it is of the highest standards in terms of cabinetry. So it does come down to how many handle the product and their mark ups and freight.
I have heard the Salk speaker but not the Joseph. So based on drivers they are comps.
I have not heard the Revel you site and it measures well.
However the speakers Swerd references have well known and very well made drivers. I suspect the Revel speakers have drivers contracted out to Chinese jobbers, which would make that speaker not a comp for me.
Well made drivers matter in terms of consistent performance and longevity. Those attributes cost money.
The Salk is a very good speaker indeed. The only thing I had reservation about was in fact the high end. I don't know if it was because of the tweeter, or because it was driven from a tube amp, which I suspect of clipping. Soft or hard I don't like either, it's just a matter of degree!