There's the recently announce Archos 101 which
might be suitable for pdfs.
http://www.archos.com/products/ta/ar...try=us&lang=en
Pricing looks good at <£300.
However it's screen resolution is only 1024x600. Fine if you're happy scrolling up and down a single page, but not quite good enough (IMO) if you want to see a full page at a time.
Also I'm not sure about applications for dispalying pdfs. Adobe are supposed to have one for Android OS, but all I've found are dead links to it.