Given how precise your specs are, you surely have an offer in hand so you tell us, what’s price being asked for that?
You can use the tool at the top of the page titled ‘pricescope your diamond’ to find other offers of similar stones from the dealers who advertise here although hearts aren''t all that popular in the database so you may not be able to get all that specific. You may find this useful in deciding if the offer you’ve received is reasonable or not but do be careful to make sure you are really comparing similar items. There’s a lot of malarkey out there.