I don't want you to lose your optimism, but eBay will consider crypto payments soon. Thus, your market will lose immediately. As VOD said, many tried before and failed. The crypto market isn't a safe investment due to the nature of crypto itself. The only real deals that can be made on your market are those with similarity to the crypto concept, such as scripts, Games, AI tools, and non-physicals in general. However, many sites have already started and are still running. Good luck to you, bro.