Don't worry about it. It's a taken of my appreciation for your business, and friendship.
没关系的。这是向你表示我们在生意及友谊上的一点心意。
We hope this will be a good start for profitable business relations and assure you that your offer will receive our careful consideration.
希望这将是我们互利商业往来的良好开端。我们保证将对贵方的报价予以认真的考虑。