Agilent 53147A. Why do they go for so little $?

[Jwalling]

I'm curious about why these go for so cheap?
A power meter, 20GHz counter, and DMM. Seems to be a lot of bang for the buck...
http://www.ebay.com/itm/AGILENT-53147A-MICROWAVE-FREQ-COUNTER-POWER-METER-DVM-10HZ-20GHZ-Opts-NICE-/282580077493?epid=1604123387&hash=item41cb15cbb5:g:hBcAAOSwzQhZcPaH

Even has the oven and battery options.

There any many others in this price range.
Why buy a 53132A/31A for a bit less? 

[edavid]

The 53131A and 53132A are much better counters for non-microwave measurements.  They offer 10 or 12 digits/second of resolution, independent of input frequency.

CW microwave counters don't have that many applications.

[PA0PBZ]

Counter only to 1Hz resolution
DVM only 50V DC
You need a sensor  (not included) for the power measurement

[TheSteve]

I paid 1/3 the price for mine compared to the one in the auction you linked to. The previous replies have pretty much summed up why they don't replace a 5313x counter. At the price I paid I think they are insanely good value for money. A power meter and a 20 GHz frequency counter. You just have to understand the limitations.

[alm]

If you plan to use the power meter, expect to pay a few hundred USD for a power sensor in guaranteed working condition. Any power sensor sold as 'untested' is likely blown and unrepairable.