"Hi X
While we do our best to value manage our product, quality is always our first priority. We ensure our products are of a high standard by using high quality suppliers and dedicating the time to make sure your purchase is perfect.
As far as value for money goes I can assure you that you have made a great choice."
Just always remember - even if it annoys the heck out of you as the creator - in convo's you need to be the sales person, put on your business face and sell, sell, sell. It's not personal, it is just business