Used Bookshelf up to $3k

I'd just like to see how what something different sounds like.

High-end speaker preferences are highly subjective, best to listen for yourself at high-end audio stores and shows.  

I do not believe the audio store sound will sound the same as my home. Also, while there are a few stores about an hour way, they have very little to offer in used speakers in my price range. 

These Fritz Carreras are worth a look.  Also agree the Reference 3a De Capo would be interesting.  Best of luck. 

https://www.usaudiomart.com/details/650241637-fritz-carrera-be-bookshelf-speakers/

I recently bought a pair of Studio Electric M4.    They are right around your budget new and they often have show demos for sale for a few hundred less.  Great speaker.   

A gently used pair of Harbeth  M30.1's can be had at or under your budget..

Quite possibly one of the most beautifully voiced stand mount speakers ever produced...