Of this number, 491 were yellow and 187 were white, according to the GSX Registry. Of the 678 cars, 199 had four-speed manual transmissions, and 479 were optional automatics. 278 had standard 455 engines, while the other 400 were Stage 1 powered.
In 1970, it cost less than $2,000 to add the Stage 1 engine upgrade, but today, these rare vehicles will cost you a pretty penny. The average price of a Buick GSX Stage 1 is $121,620, though the price varies quite a bit depending on vehicle condition and mileage.