As several people have noted, if you get to the official sight early enough (www.alcatrazcruises.com), you can get a ticket for a reasonable price. But we just booked tickets almost a month in advance for an evening tour in early August and they were booked the entire weekend we wanted. Instead we had to buy through something called Alcatraz Tickets and pay an extra $10 a head. And if you read the fine print, you see that Alcatraz Tickets provides absolutely nothing at all; they just buy out a bunch of reserved seats with Alcatraz Cruises and charge you extra for the privilege of booking through them. What a ripoff!