Best Used Speaker for Around $5000??

As I wrote in your other thread, I would look at higher sensitivity speakers with a spec in the mid 90s dB.

Take a look at the Daedalus Audio DA-RMa loudspeakers. I believe they are available with a home trial. Highly regarded by Daedalus owners.

I usually avoid the "you rarely see them for sale used" cliche, but in this case it's true, and I believe it's really because owners love them.

Tvad: Do you think my XA-30.5 would be ok with the Daedalus Ulysses? I read one of your previous threads where you were considering trying the Ulysses with a XA-60.5's... What do you think they'd be like with the XA-30.5?

although hawks do not fall into desired efficiency rating, but they're very stable on impedance and still consider to be a good match to a low powered amplifier tube or solid state.
i would suggest within your specified budget researching larger power amplifier and speaker combination which more likely no doubt bump you an upgrade towards versatility of a full range high resolution sound. for (IMHO)overpriced pass X 30.5 you can find quite an array of more affordable and more powerful amps. to my experience high efficiency speakers do compromise the full range resolution or even the sensitivity or efficiency rating is bumped up for marketing (for instance B&W or Joseph). if you're still attached to your current amp, and I agree it's great and honestly rated, i would suggest adding powered subwoofer or pair (very impressed with aerial one although might be large for your needs) but the totem sub (or pair of such) are relatively small and will substantially help you for less money spent.

my experience listening to hawks powered by plinius integrated gave me an impression that they are very natural in the small room listening for any kinds of music. adding sub will get you more presentation and obviously fuller range.

What do you think they'd be like with the XA-30.5?
Roor (Threads | Answers | This Thread)

If they interest you, then I'd suggest buying a pair and taking advantage of the home trial policy.

From my experience, Lou (the builder of Daedalus speakers) is pretty honest and accurate with his sensitivity and impedance measurements.

There are a few Daedalus owners who participate in the forums, including Almarg. Perhaps they'll chime in.