I watch for clear plastic storage boxes at thrift stores and garage sales. Sometimes a great deal is in a box already. One time there was a huge nice Rubbermaid container that held a full size christmas tree. It was only $5.00. If I had the room in my car (this was not my first sale of the day), I would have bought the tree IN the container and left the tree!
Yah never know what or where you'll find what you NEED! LOL