I'm thinking of answering in this way:
My name is Justine Collins, I am the owner of singleB. Thanks for your interest in my designs. I've noticed that you've sent several very brief requests for price quotes without ever acknowledging my replies. Normally, when people ask for a quote, they include a civil greeting along with their name and details like ring sizes and what karat of gold they are interested in. Without those things (and the history of asking for quotes without any sort of reply), your demand makes me think that you are not serious about this and that you are wasting my time.
So, I wish a cheerful good afternoon to you. If you would like to do business with me (and fortunately, I'm in a position where I don't need your business and can tell you to take a hike with a smile on my face) you can send me an actual email (perhaps not from your phone?) and treat me like a human being. I don't need your business, and you should remember how to ask for things with a modicum of politeness. Pretend that you are in an actual jewelry shop talking to the person who might make your rings. Would you approach a total stranger with "what be the total cost if this set was made in gold?". I don't think so. And it would be "what WOULD be the total cost if this set WERE made in gold?".
I probably won't though. I think I'll just reply with the cost (plus my extra fee for jerks) and no other text. I tried to be polite on the last few emails from this person and still nothing. Am I overreacting? Being too sensitive?