Your business idea has merit – real and meaningful merit – if you can prove that there is sufficient (and sustainable) demand for your product or service at a price that means you will derive a fair profit.
GOOD Someone else is already selling a similar product or service in the marketplace
BETTER You can prove that customers are interested in buying your product or service, in preference to others in the marketplace
BEST You can prove that customers are prepared to pay for your product or service (think pre-orders, like off-the-plan sales of apartments).
Focus on this first. Nothing else matters until you do.