The Price is Right expanded from a 1/2 hour to a 1 hour format in November of 1975. The frightening thing is that I remember this switch like it was yesterday, and it has as much resonance for me as Nixon’s resignation or any of the other major events of the 1970s.

One interesting fact we learn from the The Price is Right website is:

What are the grounds for a game being retired?
Games are retired because they don’t seem to spark the same enthusiasm of other games.

This in contrast to those games that incite widespread pandemonium, I suppose. Apparently there have been other changes at TPIR:

Due to Pearson Television’s acquisition of Goodson-Price Productions, Pearson has implemented creative changes to The Price Is Right, which will enhance the long-running series… A search for new models is underway and although Janice Pennington and Kathleen Bradley will no longer appear as “Barker’s Beauties,” they are expected to continue their association with Pearson Television through new projects under development.

Janice Pennington has been a model on the show since 1972. She was “Playboy Playmate of the Month” for May 1971.

Kathleen Bradley has been with the show since 1990.