When you're writing spec scripts, the sky's the limit.
When you're in low-budget land you have to write to the level you can afford to shoot. And as I just showed, we haven't even glanced at story considerations and we've already spent almost $25,000.
It's hard to write a great screenplay, as is demonstrated by countless films every week. It's even harder to write a great screenplay that you can afford to shoot.
Which is where I am now. I'm writing the sequel to my second film(that's about to get picked up--the company wants a sequel) and I'm scouting locations before I've written the scene in question. I need a place to set the final scene, so we went looking at places we can get access to. Places that are visually interesting and/or add to our production value by using them.
And I'd be lying if I didn't tell you it's a bitch. It's restrictive. It's more difficult than just following the story where it leads you.
But if you're a low-budget filmmaker then you do what you have to do to continue making films.