i guess Advantest R3465 (9KHz - 8GHz, 300Hz - 5MHz RBW) can be added to $500 - $2000 list. i got mine for $600 due to its advertised as "as is" and some defects (dead battery and out of cal). you still can find a working R3465 at a bit more than $1000 sold in ebay, and one seller selling it at nearly $2000. i guess it will depends on how long the seller want to keep it in their shelf (the higher the price the longer it will be before it find its buyer).
few other Advantest SA units (3GHz - 8GHz) also still sold at around $1K in ebay, some are $500. there is currently one Advantest R3267 (100Hz - 8GHz, 1Hz - 10MHz RBW) sold as "as is" (keyboard controller fault) at $500. if you are lucky, the power to it got shorted or disconnected due to some passive burnt out, if you are unlucky, the keyboard controller chip is dead, and if you are unlucky unlucky, the chip is unobtanium. i cant take the risk, maybe you can communicate further with the seller on the situation.
One thing about R3465 is its a "Modulation" Spectrum Analyzer, i'm not entirely sure what is, but from the spec sheet
http://www.testequipmenthq.com/datasheets/ADVANTEST-R3465-Datasheet.pdf it can do constellation and eye diagram plot and some other measurements in "Transient" mode (normal SA function is "CW" mode), i guess it has something with radio communication CDMA, GSM etc. i dont know how to use it (its there) and have no proper signal for it to test the function. so i believe it can add values to the SA functions.
and edited ps: esp for new kids familiar with modern gadgetries, this thing is a 17kg relic, it can wear out your backbone pretty soon if you keep moving it, like what i feel right now... thought you may get warned from this... the heaviest in my arsenal right now, but not the most expensive.. fwiw, ymmv.
stock photo...