Looking for a better rate for an upcoming stay in Courtyard By Marriott San Diego Airport/Liberty Station

Check in: 27 Apr 2011
Check out: 2 May 2011 (total 5 nights)

The best I can get directly on Marriott.com is $175 + tax for the first two nights, followed by $165 + tax for the following 3 nights.

Am hoping that some kind soul will find something a bit cheaper than that - ideally after a flexible rate with a King room, but will look at all options!