Betty, Andrew and I visited Blackline Supply this past week, a locally owned art and architecture materials shop on campus. They have all kinds of construction materials, but what was most notable to me, was their affordable and high quality wood. I believe a 3x24 inch sheet was around 3$, which means a full sheet to fill our laser bed would be about 12$. They're pretty close by, located in the basement of the McKinley Foundation on campus - go pay them a visit!