Yep, you're missing something. I use a Mac Mini as my computer. $599. I also have an 8" Xenarc touchscreen, which is more than the 7" screen. $349.
My point was you simply can't argue that an iPad is somehow 'inferior' because it is more stealable. ALL car PC gear is up for grabs around thieves. Whatever parts you leave behind - screen, PC, keyboards, mice, are all just as easy to steal whether it says Lilliput or Apple on it. It doesn't make any sense that a thief would steal only the mobo but not memory, HDD or the DVD drive, screen or other gear.
As for one piece being more expensive to replace, maybe. On the other hand, maybe you could have it repaired for less than a new one. Of course, it IS a double edged sword. I suppose we should have stuck with these to keep that from happening with our cell phones. Sure would make repairs cheaper:
http://djlulu.com/BagPhone.jpg
I'd expect the price of the iPad to drop going forward anyhow. In a couple of years, you'll get them in blister packs at Wal-mart checkouts.