Text of an average book is 100,000 letters; with a very smart and optimized compression/prediction algorithm (which hopefully is far smaller than 1GB), it is reasonable to expect a single char to be less than half a byte in size, so 50kB per book (saving without covers of course), this would mean around 20,000 books in a GB (not really, the compression algorithm probably also takes quite some MBs)— which should be enough for quite some time.
Yeah, but I don’t know whether you’ve recently taken a look in one of the local newspapers— being able to select topics you want to read about may very well be worth the extra effort (also, fun of course)