What makes a high $$$ cartridge high $$$?

From what I can tell, not through my own experience yet, there is consensus that going up the price ladder with cartridges pays performance dividends. The range of prices is pretty wide and I am curious what is the central issue in driving cart prices. Is it research and development technology, materials, production costs, market dynamics (luxury pricing), brand value extraction, etc. Maybe it is the same as with amps, speakers, etc., but somehow carts seem different.

Where does the price/performance curve start to flatten $500, $1K, $2K ?