UT southwestern (Parkland/childrens/ect) property warehouse has an auction of excess equipment once or twice a year. My friend picked one up there or if you are a school teacher you can take whatever you want for free as long as you have a school ID or a letter from a school official authorizing you to pick up equipment for your school district.
http://www8.utsouthwestern.edu/utsw/hom ... index.html
Contact them and see when their next auction is.
Oops didn't notice ur in austin but UT should have a similar warehouse.