hmm, I would have assumed the writer's guild rules would still apply even if you're doing an indie film.
A Tier-1 has benefits such as $108/day toward healthcare, retirement. Pay rates in the range of $21-26/hr.
That said, i know of plenty of super-low budget indies that are just too small to use the contract -- the union often doesn't mind, and union workers will still do these 'passion projects' because they love the work