Yeah, my pro novel is a tie-in as well, and isn't any different from fanfic. And my writing has gotten better since I wrote it--I'd much rather someone who wanted a notion of how I write read either the sample I'd send or, say, "The Doll Army" or Lines of Descent than Quantum Leap: Odyssey or the fifteen odd book reviews I did when I was still bothering. Heck, even as a reviewer, I'd use some of my LJ reviews as better writing samples than my published reviews.

Of course, if I'd gone through with my plan to try my hand at a Harlequin, I might have cause to be ashamed of myself, because that would just be done to net some cash...