It's the cart before the horse thing. If you are selling only 100 images per 5 months, your market is minuscule, and the last thing you want to do is pay the cost of customer acquisition by yourself. Even if it's only labor hours, you will not have the time to generate new content, which is what you need to find your market.
To summarize, figure out what you can sell successfully, only then risk it to go alone. Else, you won't make any money. At all.