For $12 at walmart, I got a huge piece of foam that happens to fit perfectly in the huge hard suitcase that I discovered in the basement! I was planning on glueing it in, but it stays just fine by being pushed real hard.
For another $12, I got a 100' extension cord to go with it.
Here's a look!
The case measures about 2.5' x 2.5'
Instead of spending $150+ on a pelican or other commercial case, I spent $24 on this setup (+ the gracious donation by my dad of a dust-covered suitcase that hadn't been used in years)! I love DIY solutions that come together nicely :-)