Also, HP/Agilent/Keysight and Rhode & Schwarz, probably the biggest competitors' brand names command pretty decent price premiums across the market, so it stands to reason other brands making similar products would end up cheaper.
I think part, at least on the Anritsu side, is that they seem to emphasize portable units and units designed for antenna testing and requiring an option for regular spectrum analyzer functionality - a lot of people think going into their shopping that they're after a benchtop instrument, and there aren't nearly as many models or as much availability.
I've got a portable Anritsu MS2721B, and while the sweep speed is a bit slower than many benchtop units, I quite like it, the level of functionality and noise floor are impressive for the price I paid.