If your primary objective is EQNs for elite status, as another poster said, look up the thread about Rewarding Nights whereby you can essentially buy EQNs for ~$10 each.

If you're doing it for the Megabonus Cat 1-4 certs or any other reason, try doing a broad search based upon a hotel feature (e.g., airport shuttle) for specific nights across as wide of a region that will work for you. Then, whittle down to under 300 results, then sort by price. Selecting AAA rate might help. When results exceed 300, you can't sort by price because Marriott.com returns a "too many results" error, but under that quantity you can.