>where I suspect they will get stolen relatively frequently
I think your assumption is even more flawed. Textbooks are replaced every 3+ years or so, that's a given. You're worried about something that might happen.
That's not a given. According to the answers on Quora[1] it seems like 7 - 10 years is more realistic.
> You're worried about something that might happen.
I assure you, iPads will get stolen, it's merely question of how often and my suspicion is they will get stolen more often than textbooks do, which he neglects to take into account in his calculations.
[1]: http://www.quora.com/How-often-does-a-primary-and-secondary-...
What if the family can't pay the deposit?
And I'm not necessarily suggesting that the student or the students family is stealing it. How tempting would a room full of iPads be to a thief? Or how about a group of teenagers at a bus stop / at the mall / somewhere not watching their backpacks?
> Anecdotal, I realize.
All I have is speculation, so I think an anecdote is acceptable :)