What to ask when buying used speakers?

@ghdprentice You are familiar with the house sound of the speakers you want and speaker you don’t want? So, you have a short list of speakers that you know you will like if received in good working order?

In this case yes, while I do not have an option to demo this model anywhere close, I am familiar with the house sound and confident I would like it. On the other hand, I have little experience with other brands, and am wondering what I might be missing. My master plan was to visit a show in the spring and do my best to eliminate those brands on my list that are not a fit, house sound-wise. Not the best place to do that, but I am confident I could whittle things down a bit.

Thanks everyone, lots of food for thought here. While this particular situation is with a reputable online dealer, the private sales experience and feedback is very useful. I will have to decide if I want to wait and hear some more speakers or grab a pretty good deal with relatively low risk.

@soix I have avoided posting any budget or brand names to prevent the discussion from devolving into specific speaker recommendations. The feedback here has been very useful and I would say mostly in favor of used purchases with proper due diligence. Thanks everyone. 

Just an update here, I did end up purchasing a used pair of KEF Reference 1's from TMR. The feedback here was very helpful and allowed me to proceed with confidence. Granted it was pretty low risk as they were certified pre-owned and backed up by their guarantees. I have had them in place for four days now and they are a great upgrade from my LS50's. 

Having been a KEF listener for some time now, I was confident that I would like the sound. I have a list of speaker brands that I still want to hear and will be attending a show, likely AXPONA, in the spring to get an idea of other house sounds.

The deal and the time were right with these speakers, and I am very happy with the results. Thanks again for all the feedback!

Will do.

@yyzsantabarbara The chain is a custom Pi/Allo streamer -> Schiit Gumby -> Benchmark LA4 -> Coda #8. I am now looking at upgrades for the streamer and the DAC is probably due.