Carpool a charter plane? (Trying to find cheapest way to fly from San Juan to Culebra)?

Is there a way to find out of there are others looking for the same charter plane as I am, and can get a group of strangers together to rent the plane? Sort of like a carpool..

I am looking to fly from San Juan to Culebra in July and the flights are around $130 RT pp, which is great, but tacked ontop of my cost to fly from Orlando to San Juan makes for a pretty high dollar vacation. I have found many charter planes that offer flights from SJ to Culebra but it's just me and my boyfriend. If I could find another couple or a few others to join it would be perfect! Since you have to fly or take the ferry if you want to get to Culebra, I would imagine there would be other people wanting to make the same trip. Any suggestions would be appreciated! Thanks :)