1950 Buick Riviera convertible Striking Classic Buick Convertible boasts a 4 Speed Automatic and 496 CID V8 . 22,216 Page Views QuickView #1222-HOU $55,000 S-O-L-D 1966 Buick Electra 225 Convertible Prodigious Yellow Classic Buick Convertible boasts a 401 V8 engine. 2,632 Page Views QuickView #2261-TPA $29,000 Buick Convertible For Sale. Buick made 2,964 of the Series 70 convertibles in 1950; this car is a Model 76C, selling new for $2,981, and weighing in at around 4,300 pounds-an astounding $0.69 a pound! Wouldn't be so quick to dismiss her, Charlie, as we've seen these cars go well into the six-figures lately-no joke (nearly $35.00 a pound).