I think this is one of the threads I was remembering…Guesses to value
There may be some information in it to help you. I understand the frustration a bit. When I was young we had to sell a family furniture business, but we at least were able to have a going out of business sale. When my mom passed we used an auction house, because she had a lot of pretty valuable items. Yes, they took a substantial sum, but it was very good to have someone else do the work for us, because it was overwhelming, and there was no way any of us wanted to take the time to sell things online.