Let's review my options:
The Courtyard Waikiki Beach is $193 plus taxes and no extra fees. It includes an upgrade and 2,000 bonus points, per a Marriott members-only promotion. However, amenities/perks are pretty limited to non-existent at a limited-service Courtyard.
The Laylow, Autograph Collection is $187 plus taxes and what the hotel calls a daily "destination amenity fee" of $25. That's affordable, but the amenities/perks are, at best, unknown and, at worst, lack.
The Waikiki Beach Marriott Resort & Spa is $195 for my dates plus taxes and a daily "resort fee" of $35. Its amenities/perks are known to basically amount to a theoretical upgrade and a buffet breakfast.
Now, let's compare to Starwood.
The Westin Moana Surfrider is $275 plus taxes. While more expensive, you get lounge access. In a place like Hawaii that's easily $55 a day for breakfast, drinks, and dinner -- especially if you make the most of it. Plus, there's no resort fee.
The Royal Hawaiian, a Luxury Collection Resort is $310 plus taxes and a daily "resort fee of $36.65. Usual SPG platinum benefits apply, I presume.
So, it looks like the Moana Surfrider is the best value. Especially since I don't really need anymore Marriott nights as I've already re-qualified.