It's not about reaching a level, it's a question of: are you producing content someone might actually need? What market are you interested in? What is the profile of your potential client? If you just want to improve yourself and produce better art, just carry on practicing. But if you want to start selling you need to think like an enterpreneur
Damn, i wanna write a book so for once people would understand that there is no specific skill level required to work in the creative industry, it just takes a certain mindset. (Do i sound like a guru yet?! Lol.)