Most likely because there's no regulations on what they can charge. I'll agree... $150 is expensive. You might have better, and cheaper, luck finding an IEMI unlock somewhere online... as opposed to using your provider's unlock.
I followed that procedure but used evasi0n instead.
Everything still works. However, when I put in a SIM from a different betwork, it still says SIM not activated.
I thought the jailbreak unlocks the phone completely?