Exactly. A decent digital communication, spectrum or vector network analyser from the likes of Keysight (AKA HP or Agilent) or R&S is crazy money – many thousands.

Compared to any piece of "proper" test and measurement equipment even if Flipper 1 is $1k it's a steal, for example. Heck, the last thing I put on a grant application was a 220 GHz AWG that was something like $1.5m. Admittedly quite different from a single m2 plugin socket but a 1 GHz spectrum analyser starts at $2.4k and everything fancier is "price on application" [0].

I realise this is not the same piece of kit as Flipper One, but with the right daughter boards, hackability, and <s>graduate student</s> labour I imagine you could do a lot (I am interested in RF at <1 GHz for NMR reasons as well as electronic Larmor frequencies at ~100 GHz frequencies). Their SDR daughter boards are designed for communication but there's a whole world of academic nerds who do weird things and would love a genuinely open, hackable broadband SDR (they exist, with limitations! I have a lime SDR somewhere…)

[0] https://www.rohde-schwarz.com/us/products/test-and-measureme...