Sometimes as an artist you have to say no. I've been approached to do a couple of murals. I accepted one and declined the other. Why? The pay was good, materials were to be bought from me, the issue was the content. I know my style, methods and my capabilities. Could I have done the mural in question? Yeah. Could I have done it without a ton of headache? No.
At some point there is a point where there is no return on the investment. Sure I could have gotten a bunch of art materials, been paid an hourly wage plus some cash.
But as I researched the content for the mural to create that first sketch I realized I didn't know a lot about the intended subject nor could I get into the subject. The more I reseached the more I realized the less I liked it. So today I declined the offer.
I hate to say no to an offer like that, it's money that comes in from ART and well that feels good, but the road to the goal has to feel good too, otherwise it's just not worth it