Yes, it does have a cylinder keyed to the ignition key, but is that really worth that much money? Maybe to you, but not to me. I've been installing a basic type helmet locks on motorcycles as long as I can remember ... and I never felt inconvenienced having a different key on my key ring for it.
So, I picked up a Motion-Pro helmet lock down a CycleGear this morning for $20, slapped in on and we're good. I've seen them on eBay and other places, like Amazon for around $15.