1988 Sound Labs electrostatic model A3 pair

My aunt has a pair of these. She has asked me to find out how much they're worth. Shes considering selling them to the right buyer. She also has a big black speaker tower called The Ultimate circa the same age. Looks simular to the A3's only larger. I have pictures of all three. I can email or text them to you.

Thanks for your help. I just joined the site today. :)

Jeff