Valid point. Earlier I came down on the side of not paying and also thinking being asked is a sign of more red flags to come. I hadn't considered that the guy who organized it might not be thinking of himself as a band leader, so he might not be thinking about it from the invitees' perspective. But I still think it's pretty tacky to take a leadership role in organizing a band and then expect the invitees to pay, at least for that initial audition. However, I also see nothing with the "BL" (the guy who organized it and will apparently make the selections) saying that a condition of being selected is that you'll pay your share of future studio rental costs. But the initial audition, nah.
The band leader might just be clueless or inexperienced, but it should have been pretty easy to tell that from any conversations or exchanges prior to showing up for the audition. If he was experienced, then I'd think the request was a red flag and stay away. If he's inexperienced, well, maybe he could be given some slack.
i wasn't actually making a point - just saying i've run into this situation a couple times.
sometimes being that inexperienced can be a red flag of its own unless someone mentors the guy or takes over BL duties, and not everyone wants to do that.