If I remember correctly, average price for a one-day pass is about $30. Saturday is generally the most expensive day since it's the most popular, but it only costs about $5 more. (Sorry if my memory is a little hazy, but I've been pre-registering for the last 2-3 years.) But yes, you can only get those passes after waiting in line at the convention, and unlike the pre and early registration badges, they do not require you to bring a photo ID. And like one of the previous posters said, for exact rates, check the Fanime website a little later on, like around late April or early May. They should be up by then, and you'll be able to get a better idea of how much money you'll need for not only the badge, but also merchandise and food.