When we meet at the Charles Cryer, there's a flat entry fee of £3 per visit, whether writer, actor or spectator. We have to pay to hire the space and this seems the fairest way to share that cost. (This doesn't apply to actors cast in a production, attending rehearsals)
The advantage of something like EoL is that it brings creative people together. We all want to gain satisfaction and enjoyment from what we do and use it to help us progress. Projects cost money and no one likes to make a loss, but if you've something interesting in mind, feel free to suggest it and we'll work it out from there.
With regard to costs involved for a project... maybe you're a short-film maker looking for writers and actors... maybe you're an actor wishing to collaborate with others on a new showreel or experimental theatre...