Budget is definitely important for a successful business, but it is not everything! As a young entrepreneur, I started a similar business earlier in my career selling eyeglasses on eBay. I created an eBay store, worked on advertising, and was fortunate with my results. I would love to speak with you about starting a website and marketing effectively to consumers with a very small budget. The biggest recommendation I can provide is to test different services at a low budget to see what works. Rather than spending thousands of dollars on a marketing agency, there are many services that can help your iPhone case business in marketing effectively. Feel free to reach out to me!