Plus all the expenses needed to get the station running. Once you factor in maintenance, electricity, and other operating costs, he may not be saving much.
HD subchannels are relatively cheap to lease because the operating and maintenance costs of an existing HD station are the same with or without subchannels. The only cost incurred is the licensing fee, but that gets factored into the lease. I'm not saying that this is what Rehan is going to do. I've just worked in this industry long enough to know how the game is played.