Re: Sample Only
I would consider myself an expert in the art of watching movies.
But certaintly not writing.
And not the business of it. So take my opinion for what it's worth.
Unless you're a truly prolific writer, and can bang out a polished, elite script in 2-3 months, I don't see a purpose of writing a script that you think, and maybe even know, will only be used as a sample.
I would also argue that a marketable script can show off a writer's skillset moreso than a non-marketable one.
If the idea is so high budget that it could never get made (we're talking sci-fi and fantasy here), I would suggest a novel.