Considering female pastels are worth under $200 as babies right now, and $650-$1000 around breeding size, I wouldnt be surprised about someone asking $3k for a female ivory.
Another thing you have to remember, three years ago yellow belly prices were much higher. You could not get a male yb for $100 shipped. Female ybs are going for $100-$200 this year and its a safe bet that in three years when that generation is breeding an adult female ivory will be worth a lot less.