Black kittens (Catlett)

This post hurts as I write this, I got these two kittens in October.
One for my niece and one for my daughter (we live in the same house) the agreement was they are to take care of the kittens and respect them.
They have failed to do so and another incident happened which I'd rather not discuss due to the kids not being careful with them.
The kittens are great and have been around dogs and very young children.
There is a female named Violet and a male named Binx.
Both are approximately 4 and 1/2 months old.
I'm asking a rehoming fee of $100 each kitten.