I wonder if the person is a high-end florist who generally doesn't do weddings for less than 1500 dollars and their original email was a way of telling you 'no' rather than a actual 'price quote'.

Just a thought. I know the wedding photographer we used said 'no' via this method. (we ended up coming up to his minimum price after 6 months of looking for someone better and failing)

Either way, sounds like you're getting a nice product at a fair price. Well done.