Acura was the first Japanese luxury car to arrive on the market. Lexus was the second. Affinity the third.
In 2002: Acura sold 143, 708 models. Lexus sold 71,206. Affinity sold 34,809.
The ratio is almost a perfect 4:2:1
Determine your niche today and ship tomorrow. There will be plenty of time to refine. First, let your customers interact with your product and listen to their feedback. Then modify, modify, modify.
Hiding behind a keyboard anticipating perfection is as hopeless as whipping the cart and expecting the horse to run.