For those looking for hotels you can still find rooms at:
Marriott Courtyard (across the street from the event - https://www.marriott.com/hotels/travel/pitcy-courtyard-pittsburgh-downtown/) for $239/nt
or the Kimpton Monaco (very nice hotel a few blocks away but still closer than the Omni - http://www.monaco-pittsburgh.com/) for $218/nt.
Not quite as cheap as the room block but both are closer and good (or very nice in the case of Kimpton) hotels.