I see plenty that go for real cheap or even free. They are a special needs fish and most people have no business keeping one so you end up with a lot of people trying to rehome theres at 10-12".
If they are a spectacular wild caught pair or something you can get a decent price for them. If they are an average Dovii you are not going to get much. Plus there are going to only be a couple people in most areas other then so cal that can even properly house a pair so that really limits there market.