This from our Rich Get Richer vault: Multimillionaire producer-director Steven Spielberg will realize another $75 million from the record-breaking videocassette release of “E. T.: The Extra-Terrestrial,” according to a report in Daily Variety. The trade paper quoted “reliable sources” as saying Spielberg negotiated an unprecedented $5 share of each “E. T.” video sale (MCA Home Video also gets $5 per cassette). About 15 million cassettes retailing at $19.95 each have been sold--a record for a video release. Spielberg, whose net worth was estimated at $225 million by Forbes magazine earlier this year, would therefore reap a windfall of $75 million.