There are plenty of inexpensive RPi casings available ranging from $5 to over $50! They are almost all, however, somewhat boring–so I started a search for another casing I could use that would give my RPi setup some personality. I came across an old [broken] Sega Dreamcast console for about $5. The Dreamcast console has a pop-up disc drive opening controlled by a spring-loaded button, a simple on-off power button, as well as some built-in ports in its plastic casing in the back and front for power/AV cords and controller connections, respectively.
I figured this would be a good start for my project, so I picked it up and quickly began the disassembly process. I was surprised how easy the console came apart using a simple screwdriver. Within 15 minutes, I was able to separate the top and bottom halves of the casing, remove the disc drive reader, motherboard, and power supply. I came across a small fan that I chose to leave in place to allow some ventilation if I chose to at some point in the future.