Canonicals for Real Estate

[SteveCastaneda]

A real estate site has a landing page for a particular zip code:

site.com/zip/99999

On this page, there are links which add arguments to the URL, resulting in structures like this:

site.com/zip/99999?maxprice=1000000&maxbeds=3

My question is on using a canonical URL for the pages with arguments.  These pages may have lots of duplicate content, so should I direct search engines back to the base URL for the search? (site.com/zip/99999)

A side note is that these pages with arguments could have no listings returned (no listings found) or could come back with listings (then it wouldn't be duplicate), but that can change on a day to day basis.

[edwardlewis]

I would stick to optimising the main site.com/zip/99999 type pages

As the other ones have no particularly unique content and the fact that they arent permanent pages (eg when no listings) means you will never be able build links into them

[SteveCastaneda]

This is what my intuition was telling me too.  I think the only thing that made me re-consider was that I started receiving traffic for those links with arguments.

Thanks for your input!