I would like to know as well.
Also there is this reasonably priced option, which won't be metrology grade, but could be perfect for day to day use to avoid wear on the metrology grade kit:
https://www.ebay.com/itm/293553480590<rant>
On another note, there are some faulty, old or very old, 8720's on the Keysight store. (8720C/8720D) I've been trying to talk them down in price but not having much luck.
There is a 'won't power up' 8720D which has option 400 which would have been nice and was my first option.
The 8720C looks like it has a low band fault and a very dim screen and is cheaper but still not really very reasonably priced.
Seemed to me they are being a bit optimistic with what they are asking, given the parts needed to repair are almost all unobtanium or quite expensive even on eBay, so repair is a fairly big gamble as the faults are unknown.
Longevity once it is working is an unknown too.
It is hard to see anyone buying these for parts to keep another old analyzer going at the high prices they want.
For me there is also the high additional costs of shipping and tax, not to mention cal. kits, cables etc.
So I will just wait and see what happens - there appears to be a global slowdown building steam so I think there may be some bargains in the next 12-18 months.
I concluded that Keysight have decided on a policy of keeping the prices of old gear high to prevent a ripple effect up their food chain.
I see they still accept an 8720D as a trade in on new gear so that may be part of the reasoning.
</rant>