According to lvstriphistory.com ...the clown sign appeared in 1982...and the buffet prices would probably fit that time frame...

http://lvstriphistory.com/ie/circus74.htm

"In 1982, completion of the $7 million expansion and renovation included enlarging the casino, dining and valet parking facilities, interior decoration and a new front entrance marquee. That sign, dubbed Lucky, is a 123 foot tall clown...."