I like the fact that the protestor has to have some skin in the game.
Agreed. It's comforting to know that if someone protests a person the costs will be covered assuming they're legal.

On the other side, I too have decided not to file a couple of protests due to the costs involved. I like how you guys did it by getting a group of people to split potential costs, but haven't found it easy to assemble a group. It's usually "yeah, I'd love to protest that car" which turns into "well, I didn't mean actually file a protest."