How do you sell a used Hearing Aid - Phonak B90-312T?

My father was provided a pair of Phonak B90-312T hearing aids two weeks before he passed away suddenly this summer. I am his son and wonder if there is a place to resell used hearing aids. They are practically brand new as he may have used them a dozen times at most. All packaging, extra batteries, documentation and etc are included. His documentation seems to imply they cost $5K for the pair. I am hoping to get something reasonable out of them but don’t know where to post them. They are a bit out of place for craigslist. Any advice would be appreciated.

They go on eBay. B90s go for around $1000, give or take.

For comparison, I bought Phonak M90 for about £600 on ebay.