You can submit for FREE @ some Festivals. Others charge up to One Hundred US Dollars $$$ to send in your Film or Screenplay. I’m not kidding. Everyone wants to be famous and the Festivals know this and charge up the Wazoo. What to do?
Examine Reviews for the Festival. If no Reviews exist, it’s probably a newbie Event and I’d steer clear until Reviews start popping up. Don’t just read a few reviews and submit if all appears fine. Read them all. Then email the festival and ask a question, any question. The speed of response will tell you how much they really care. Sometimes my email bounces. Beware of Festivals that use alluring words such as CANNES or HOLLYWOOD or PARIS in their names. Just because a Festival has the name of a Cool Location in its title doesn’t necessarily mean its Event is held there. If you’re cautious you will weed out the sketchy Festivals within a week and be able to narrow down your choices.
One BIG PLUS to submitting is getting producers to read your work without needing an agent. Look for those in the ABOUT US sections of Film Festival sites. I just submitted a 100k-max low budget Thriller script to a Festival looking exactly for that. If you don’t spin your wheels and $$$ chasing after Festivals that don’t line up with your style/voice/work, you’ll move to the front of the class. 
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