I've been considering whether to get a used
Canon DR-2050 from ebay. I've worked with Canon drum scanners in the past and really liked them, and I want something fairly portable.
I already have a small flatbed scanner--a Canon LiDE (they're up to 80 now; I think mine is a 30 or 60) that works great on book covers and pages that are too delicate to run through a feeder, but it's slow. It's about 1 minute/page for 300 dpi color, half a minute for 300 dpi black & white.
Right now, I usually scan pbooks on a
Fujitsu 5750-C, at work, which as far as I can tell Fujitsu no longer makes (the new version is the 6770, which might be available for as little as $6000). I don't recommend acquiring one of those for personal scanning projects; I use it 'cos it's there at work and they don't mind as long as I don't get in the way of work projects.