Spanish Subtitle Proofreading Needed (only spanish native speaker)

I have around 200 of Spanish subtitle files that accompany corporate technical-skills training videos, and I need them polished before release. The language already sits at a solid draft level, but I want... (Budget: $10 - $30 USD, Jobs: Editing, Proofreading, Spanish Translator, Subtitling & Captioning, Technical Writing, Translation)