Dennis....

If you qualify, there's always M11 or AAA. You might also want to try LPR (Local Promotion Rate), sometimes this will bring up a weekend special or some other promotion unique to the hotel that anyone can qaulify for. Then there's BAR (Best Available Rate). Usually this doesn't do anything of consequence, but every now and then it'll bring up a good deal.

Boulder can be pricey and a tough place to find a bargain. If price is really an issue and you need a Marriott branded hotel, try the Fairfield Inn north of Denver off of I-25 (I think it's at 120th street, or something like that). Nice Fairfield, several restaurants and shopping nearby, and about a half hour from Boulder.