This binder from amazon has worked great for me (about $13, sometimes it's been on sale for even cheaper though). That link should have a recommendation for matching protective sheets also
http://www.amazon.com/Avery-Durable-Binder-2-Inch-27554/dp/B0006HV8V2/ref=sr_1_1?ie=UTF8&qid=1434386924&sr=8-1&keywords=playbill+binder&pebp=1434386925451&perid=DE8CF2AD8BE045848EE6