I ordered an 8cm BD-RE from Japan for $35. Compared to a 12cm BD-RE, which stores 25GB, the 8cm variant stores 7.5GB, and was designed for use in a small range of camcorders (before including optical drives in camcorders stopped making financial sense).
Why did I buy this, if I don't own any blu-ray camcorders and have no intentions of purchasing one?
Because I'm a grown-up and I can do whatever I want. Fuck you.