I'll try to keep this brief, just as I try not to make Patreon journals too often...
So, I've got a Patreon, and i run a drawing request raffle on it. It's a little different than a regular raffle, in that your tickets aren't discarded after the drawing. Instead, every ticket you buy (at $1 each), stays in the draw for next time. If you win, all of your tickets are removed, increasing the chances for those who lost in the next drawing. Therefore, if you're patient and lucky, you can win a request for as little as $1. I believe the record for cheapest win is currently $4. Most of my patrons donate $1 per month, increasing their chances as time goes on.
I've also introduced some stretch goals, for example, if I reach $40/month, I'll start drawing 2 raffle prizes instead of one.