As a cartoonist, one advantage you have over prose writers is that after you publish your book, you can sell your original artwork in a gallery show for hundreds of dollars. This works out great financially for the artists, and at the same time works out great for the fans.
David Heatley recently posted an awesome concept diagram of a multi-media show he has in mind to do for his upcoming memoir:
Heatley’s memoir seems particularly suited to this kind of presentation — dig the home videos his father singing.
So anyways: sell your originals. Although few prose writers have taken advantage of the business model, I can see it working, especially for people who write first drafts in longhand. (Lynda Barry sells pages of her original calligraphic manuscript for Cruddy at very reasonable prices over ebay.) Who would mind this hanging on your wall?
I can’t imagine anyone ever wanting to buy my original artwork, but you never know. I better start working bigger…on better paper!