Awfully high?
Apple shipped over 1 billion devices with that functionality.
It's actually somewhat less than a billion, since early iDevices aren't compatible with the current incarnation of FaceTime or Messages, but the number is still very high. Let's say roughly 700 million devices, or a dollar per device.
And as I said, this may be reasonable. But given that FaceTime and Messages are only two of the thousands of things that iPhones are used for, and that these patents relate explicitly to the secure transport protocols used in those technologies (which are of interest to the privacy-conscious, but most users aren't even aware of), and just in relative proportion to other patented technologies involved, a dollar a device seems quite high to me.
Think of it this way: FaceTime uses H.264/AVC encoding (you can find it mentioned in the software license agreement). As I pointed out, in the US alone there are well over 600 patents involved in
just the video used to encode FaceTime. There are, presumably, other patented things involved in the transport protocol, the display, the UI, focusing the camera, light level detection, noise rejection, etc.
So looking only at FaceTime, if you take the four VirnetX patents to be worth 50 cents per device, or around 12 cents per patent per device, then the 650 other patents (a few are already Apple's) involved in encoding and decoding the video, if licensed at that same 12 cents each, would cost $80 per phone.
Now, patent licensing doesn't work that way, but my point is that unless these four patents were incredibly integral to the functioning of FaceTime and Messages, a buck a device seems high given the absurd number of other software patents involved in the device.
Of course, if it's willful infringement, the damages can be punitive, in which case high numbers are quite intentional.