I agree, it's supicious at least that a seller will not allow audition, but your choice is not to deal with that seller, and he/she must realize their unwillingness to accommodate a potential buyer limits their market. On the other hand, if your intention is to troll around and listen to speakers before you're really committed is going to be viewed by most sellers as a waist of their time, and rude on your part.
I generally would provide an audition of ANY equipment I'm trying to sell; but would qualify the buyer's readiness and commitment before hand.
As to whether you're overly prudent - I have purchased and sold many used components as a means of performing "in home" auditions. That's one of the great things about the existence of a well established used market. You will learn a lot more about the speakers and make better use of your time IMHO by doing it this way. And if you're careful it may not cost you much or any $ out of pocket - although really heavy speakers can be an issue with shipping $, or are limited to local sales.
I generally would provide an audition of ANY equipment I'm trying to sell; but would qualify the buyer's readiness and commitment before hand.
As to whether you're overly prudent - I have purchased and sold many used components as a means of performing "in home" auditions. That's one of the great things about the existence of a well established used market. You will learn a lot more about the speakers and make better use of your time IMHO by doing it this way. And if you're careful it may not cost you much or any $ out of pocket - although really heavy speakers can be an issue with shipping $, or are limited to local sales.