Does the unit cost $199 (let alone $239.40) in the first place?
If not, then why not just buy the unit elsewhere and get your books elsewhere?
Unless you're looking to join Filament Books anyway, of course.
It looks like
http://www.ebookwise.com has an eBookwise-1150 that comes with a 64MB smartmedia card for $124, and I can't see where they ask you to join anything (could be missing it, though).
If you like the looks of the device, I don't see any sense in paying double cost to get it free for joining a service you're not sure you'll use much. True, their books cost ~$10 each, so it would balance out okay if you can find your 2 a month, but that price seems a touch high to me for an e-book, though I don't think I've done an exhaustive survey.
