Reddit mentions of Mage: The Ascension Tarot

Yeah, Anazon says it's out of print and goes for $85. There's one edition that's just shy of a grand. I think that's outside my range.

http://www.amazon.com/Mage-Tarot-Deck-Ascension/dp/1565044339/ref=sr_1_1?ie=UTF8&qid=1458637754&sr=8-1&keywords=mage+the+ascension+tarot

http://www.amazon.com/Mage-Tarot-Deck-Revised-2001-04-16/dp/B01A687MRY/ref=sr_1_3?ie=UTF8&qid=1458637754&sr=8-3&keywords=mage+the+ascension+tarot

Besides all the great tips already listed by others (original Tarot and Tarot-based decks of cards especially!), I'd recommend taking a look at the many playsets published for Fiasco.

The game (that I've read but never actually played) is cool, if you like shared, GM-less storytelling (I don't), but it's not free, obviously -- however, the playbooks themselves are free, and they present an awesome tool for kickstarting your own ideas and stories, regardless of what game system you're using. They're especially useful if you're looking for character (PC, NPC) motivation, relationships, and backgrounds. Take a look:

Here's the official collection of playsets, and here's a larger unofficial one.

In case you'd like to see it in action as a writer's tool, here's a special, official playset which does exactly that: Gangster London Writer's Edition

He?

Goes from 90 to 150$ for a mint deck. Expensive, but in case you were looking for one and didn't check recently, here's your chance!