In 1973 Ferrari replaced the Dino 246 GT V6 with the Dino 308 GT4 V8. Unusually, they did not choose Pininfarina to style the car, instead opting for Bertone, where a young Marcello Gandini did the actual design. In typical Ferrari practice, construction was done at the Scaglietti works. Oddly, Ferrari asked Bertone to make the car a 2+2, as they felt this was one area the Porsche 911 had held an advantage over the 246 GT. When it debuted, the Bertone design was not well received. While it was simple and elegant, it was also very angular and slab-sided in a manner typical of Bertone's then-current wedge fetish.
If the styling was controversial, the performance certainly was not. In its original Series I form, the 3-liter all-alloy V8 cranked out 255 horsepower, which was good enough for 0 to 60 in 6.4 seconds. Top speed was claimed to be north of 150 miles per hour. Handling was excellent due to a low center of gravity, a full tube frame and four-wheel double wishbone suspension. Braking was by four-wheel discs. The ride was surprisingly good, as the low roll center and light weight allowed the use of relatively soft springs while maintaining good roll control.
Today, the car's styling is still controversial (or, in SCM terms, "unloved") and the performance is still exemplary. The GT4 offers a powerful combination of vintage Ferrari sound and feel (no power steering, a tube frame, four twin-choke Webers) and modern performance (mid-engine and IRS, as opposed to the earlier cars' front engine and live axle). Best of all, it is a Ferrari, which means it can be used for anything from FCA track days to road trips to many vintage rallies. Even better, it is affordable.
The GT4 is a great way to own a vintage Ferrari without spending a fortune. The price guide range of $15,000 to $22,500 is below that of nearly any other Ferrari listed, many of which have performance that is far inferior. The most difficult part of buying a used GT4 is finding a good one. Low price not withstanding, these cars cost as much to fix as any other Ferrari-expect to pay for a $3k major service every 15k miles, and be aware that a gearbox rebuild can run $10k.
For this reason, finding a good car is the only way to avoid fiscal self-immolation. Look for a car that has been frequently exercised and has a full service history. Don't buy a car without a comprehensive inspection by a qualified shop. Garage queens that have sat for years can cost tens of thousands of dollars to sort out, even if they look spotless.
Don't believe low mileage claims unless they are verified with years of records, and don't shun a higher mileage car, so long as the required services have been performed. Be vigilant for rust, rust, and more rust, although the fiberglass floors in the GT4 make it better than earlier cars from this perspective. Series I cars (1973-77) are the most desirable as they have no catalytic converters and more radical cams.
As far as value is concerned, a bad GT4 with serious needs is no bargain even if it is given to you for free. Conversely, paying way above book value for a totally sorted car with recent vintage tour or rally history to prove its reliability can turn out to be a wise move in the long run.
If, and this is the big if, you can find a good car, it can be a wonderful, fast, tossable entry into the world of vintage Ferraris and a cheap way to start running US-style vintage rallies. Besides, you can't see the styling from behind the wheel.