I already own a bookreader, but I'd prefer the paper version of manga anyway, they look much nicer and then you have something "real". Personally I think you should get the e-book for free with the real thing, then it would really be awesome
Right now, where I live e-books are way too expensive too, I mean, they cost the same as the actual book and they don't even have to print it, completely ridiculous D|
eReaders with eInk like the kindles need to improve a bit more before I would consider switching over. The quality is decent, but it isn't there yet. Tablets like the iPad aren't any different than reading it on the computer. I'm not about to trade reading it on an LCD with reading it on a smaller LCD. eInk needs to get better resolution so it can catch some of the finer details.
Also, when I tried reading manga on the older kindles, it took *forever* to transfer it to the device. It was close to a half-hour to transfer a single volume. I could have read the whole thing on paper in that time.