Some people use the term "sellout" to include any artist who dares to have any ambition. What really matters is doing great work and taking advantage of anything that comes your way. I say YES! I like new things, projects, plans, getting people together and trying something new, even if it's silly, then the magic happens. The people yelling "sellout" are the people yelling "no." They are the people who don't want change. But a life of creativity is all about change. Moving forward. taking chances and exploring what is next.
Be ambitious. Keep yourself busy. Think bigger. Expand your audience. Don't hobble yourself in the name of not "selling out." Try new things. If an opportunity comes along that will allow you to do more of the kind of work you want to do say YES. If an opportunity comes along with more money but not what you want to do, say NO. And that's how you make more of yourself and attract more work for yourself, not a sellout. BRAVE.
"There is no misery in art. All art is about saying yes. And all art is about its own making." John Currin