I enjoy these kinds of experiences because they can slowly teach us that there is no need to distinguish between altruism and self interests, both can (and perhaps should) overlap so that there is no distinction.
I really love pay-what-you-want, and I’m searching for ways to spread it and make it easier. It’s a way to add to a gift economy while also compensating for the fact that much of society is not flexible and some things are not up for negotiation like plane tickets or highway tolls. I would like to search for more ways to encourage it to be more flexible though!