So apparently on the website, you can't pre-register for one day. I've been told you can only do so at the con. How much does one-day badges costs?
In addition, they only need your ID to pick up a full-weekend badge, right? I've done too much moving to have a solid address, so the address on my driver's license is not the same as the address I registered with, nor will it probably be the same address by the time Fanime rolls around.
ID is for attendees who have preregistered online. You don't need so when doing at the con. They will have the prices up when the con gets closer like around May.
Also, price varies a bit depending on what day you plan on going.
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.