Wow, evidently the anticipation level of the movie is already on the rise. The only complete run of The Watchmen that's listed on ebay is already at $150.00 with over 4 days remaining.
http://cgi.ebay.com/The-WATCHMEN-1-12-SE...1QQcmdZViewItem

I think the TPB is the way to go after all.

As a matter of fact you could get him The Watchmen, The Dark Knight Returns and The Killing Joke TPB's from amazon.com for around $30.00. These are among the greatest comics of all time...

The Watchmen TPB.
http://www.amazon.com/Watchmen-Alan-Moor...0634&sr=8-1

The Killing Joke TPB.
http://www.amazon.com/Batman-Killing-Jok...0634&sr=8-3

The Dark Knight Returns TPB.
http://www.amazon.com/Batman-Knight-Retu...0634&sr=8-2

I'll keep my eyes open for a set of The Watchmen for you, but after seeing that ebay auction I wouldn't get my hopes up.

Sorry I couldn't be more helpful man...