Radio Shack used to sell "mystery boxes" for $5.95 each every so often. Each store would have a couple of dozen out on display at any one time. Each box was about 6" on a side. Sometimes you made out like a bandit, sometimes you were mad you wasted the money. Still, I'd buy two or three every time they appeared. It was corporate's way of clearing out old stock of smalls.
Redco cables has a mystery box thing. They basically give you scraps that are left over from installations and custom cables. Its cheap and usually enough to make a decent cable or three with like canare or mogami cable. I needed some short digital cables once (AES) and got the mystery box. What i got was way more expensive that what i paid. My condolences. F that company in the ear!
