I don't own an iBook. Yet.
The reason why I asked about what a business might offer for a used iBook is that, in offering to pay X amount for a used iBook, I want to know what your average used comp reseller would give for the selfsame item (ex.: if Joeblow's 2nd-Hand CPUs is paying $500 for used iBooks, I'd offer $500 to someone for their used iBook).
What works to my advantage is that I'm surrounded by locations of a technical school chain that issues their students iBooks as part of their education (it's part of their tuition). I figure this potential glut of used iBooks would drive the price down, if someone opted to sell theirs for quick cash rather than deal with the bullsh*t that using eBay would inevitably entail.
Cheap? You bet I am.