I'm not sure that either price-fixing or the rise of the chains explains that much of the variation between countries.

I grew up in Australia (which used to have book price-fixing but I think now doesn't) and now live in Seattle.

There is really only one bookstore in Australia ('Gleebooks' in Glebe, Sydney) that would beat 'Borders' in Seattle even in a moderately specialised subject area. Even so, I don't use Borders much because I work a few blocks from one of Seattle's two good bookstores.

On the other hand, Borders now has stores in Australia, and the one I have visited in Melbourne isn't anywhere near as good (which is why nice smaller stores like 'Readings' still survive). AFAICT the bookstore situation in Auckland, NZ, is even worse (both pre- and post-Borders), though I may just have not found the right place.

It's surprising that Auckland and Melbourne, both with larger populations than the Seattle area, can't support a better bookstore. Whatever is wrong with the Aus/NZ book market seems to be pretty resistant to changes in market structure. Presumably it's something to do with distance, but I don't really see why.