What has changed is how people make money off of something as basic as a transmitter. 50 years ago they just paid for the transmitter and the land it sat on. Today they not only have to pay for the transmitter, they have to pay a yearly royalty on the stander (ATSC), the modulator (8VSB) and the audio/video codecs(MPEG2/MPEG4 and Dolby AC3). As well they have to pay to trasmit the video from the station to the transmitter via fibre optic(cost per MB) or C/Ku Band(twice the cost).
"And Now for Something Completely Different..." - John Cleese (Monty Python).