Let's take a short survey of what you can buy with $300,000 USD: A Lamborghini Murcielago, fifteen Honda Civics, a reasonably-sized house for a small family, or a ViPN Black Diamond Windows Mobile Smartphone.
Yes, it blows my mind as well. Who in this great world would spend such an exorbitant price for a cell phone? I asked this question to a member of the ViPN team, named Emidio, and he replied that three people from the US, Sultanate of Oman, and Russia have expressed interest in buying this phone.
The diamond is removable so that when you decide not to use the phone, you can use the diamond in other jewelry applications. What kinds of diamonds are used? Emidio remarks: "The Diamonds are 3 carat on the back, and 0.25 on the Joystick."
Summing it up, Emidio says that "So again the price tag is because you pay for the Diamonds, not really the phone. Let's say the phone is an accessory for the diamonds." Perhaps it may be more economical to take my i-mate SP5m down to the local jeweler and have them inlay some diamonds into the keypad. Who knows.