There are several out of block downtown Marriott Rooms available for 449 a night, you can choose from the Fairfield, Courtyard, or Residence Inn. The Fairfield and Courtyard are both connected to the JW Marriott and have access to the Skywalk, and Residence Inn is by the water canal across from the JW.
If you have a large enough group, of 4 or more people, you can get a pretty reasonable per person price and have a downtown room. Just don't tell Marriott you're sleeping 8 people or whatever.
These have been going up and down all day, I suspect they will NOT LAST.