Introduce Yourself : New Stage 32 filmmaker with a marketing question by Caroline Boyd

I'm currently in post production for a short I just finished, and although I am well versed in social media marketing for projects, I'm a bit inept at the physical marketing side (making postcards, posters, etc). I want to order some postcards or posters for when we put this short film into festivals and screen it, I'm just not sure which place is the best deal for a mass order of marketing material. I know vistaprint is good for business cards and postcards, but is there a website out there that sells postcards cheaper than 25 bucks for 100?