I'm surprised more people aren't interested in this given the $200 credit.

I've been browsing the site (it's super laggy) and here are some sub-$350 options I've found for weekends in the next 2 months:

(FHR) Denver - Art Hotel $239 (assuming complementary 4th night)
(FHR) Boston - Encore $234 (assuming complementary 3rd night)
(THC) Chicago - Fairmont $299
(THC) Chicago - Royal Sonesta $261
(THC) Chicago - Palmer House $219
(THC) Miami - Mr C Coconut Grove $345
(THC) Miami - The Palms $349