I guess I'm lucky...
I guess I'm lucky in a way. Being a first time publisher, with my first adventure now scheduled for release next Monday.
Rather than a writer, which I do dabble and have been forced to create huge chunks that are changed to wordsmithy by editors and proof readers with the small publisher (Dementia 5) whom I am collaborating with in its creation.
I am an artist, but moreso a pro fantasy cartographer. Because of this, I can do what few small publishers can and that is provide an adventure gushing with top quality maps, not one or two but five or more per module. Since my work has been commissioned by publishers large and small, I know my capability.
As an illustrator, I am less experienced, but I am including my own art in my work. The publisher I am working with has made connections with many artists in the industry. I am working with three artists in my project.
Simon Turnbull is an unknown, a British Illustrator teaching in China and though has charged me more with a cover illustration, as well as a couple color pieces, he also included a dozen pieces of B/W art for no charge.
Jan Pospisil a concept artist from South Africa has been charging me, whatever I think she's worth, which has only given me a guilt complex, because as I too am a poor first time publisher, I feel I can't pay what she's worth, but she continues to create work for me. She's my primary module cover artist.
Mark Hyzer was a rare find. He's an established industry illustrator with many Magic the Gathering CCG art pieces commission by WotC. I guess he prefers pencil work, but never seems to get commissioned for that and because he is created the bulk of my beastiary in pencil, he has given me bulk rates that are lower than the other two artists. That's been a big break for me.
Regarding clipart. There's good art out there if you can find it, and if you can find it cheap (which isn't so common.)
As a graphic designer with my own studio (for my day job) I never use clipart, ever. I worked a number of shops in my career that relied heavily on clipart. Once I was doing it on my own, I never touch the stuff, except for the rare photo needs from Stock Photo services (I am not a photographer, nor do I have access to a serious camera).
Oh, but being a pro graphic designer is another break, because I can create top quality page layout, again not pay anyone for this, just more of my time involvement. Since its my project its best thing I have to invest is my time.
Although I never planned on it originally, my life skills experience and some luck has given me tools to produce a top quality gaming product, now if only it sells...
If I were less willing to part with my money to commission art from pros and semi-pros that are giving me excellent deals, I would turn to the local college's and troll for artists on really cheap, before I went to clipart.
Sorry for the long response, just my 52 cents (too much for just 2 cents!)
GP