Pricing and Selling Horses

I have a dumb question about pricing horses for sale. I'm having a little trouble with pricing horse for an appropriate amount, not to much but not to little. Does anyone have any advise or system on how you price your horses for sale. A lot of mine have 900+ stats and have average to good confirmation.

And also would you prefer seeing a horse up for private auction or be able to buy it without waiting for approval from the seller?

My general rule of thumb is about 5k per 100s, +5k for each rare gene.  I don't pay too much attention to confo (as high confo in my breeds are generally inbred or overbred in my eyes).  

With my own horses I might set a sale price 10-20k higher, and it's bid at half of what I want.  Generally though, I have my horses set on private auction, so I can look over the buyer and their breeding practices.

Thanks. I get nervous selling my horses without approving the new owner. I get super attached to my pixel ponies. I’m having trouble selling them so I was thinking I over proced them. And now that they are up for private auction I’m getting ridiculously low offers. I’m just stumped on what to do. Lol.