I don't have a problem with very good on polish, but I wouldn't consider the stone unless they are providing you with magnified images of it at the very minimum. I would be wary of very good for symmetry. And princess cuts can be beautiful or ugly, so there's just no way to choose one without pictures. An ASET image to show light return would be very helpful, also.
Very good polish is fine. We just can't offer you any advice on the stone though without actual images of the stone and an ASET to show how the stone is likely to perform. If this is a BN stone you can call ID jewelry and ask Yeukitiel to call this same stone in, he will be able to take the necessary images for you and will also beat BN's price.