That is a power windows and air '57 Super, so it would be fairly rare from that standpoint alone. No telling what the original color was, but it looks to me like it has had a cheap respray sometime in its life. I don't believe I ever saw a single-color 1957 "senior" Buick. They were largely found to be two-toned. The biggest potential issue I see is that it is setting with the body on dirt. The 1957 Buicks were profuse rusters, almost as bad as the Chryslers were. The rear bumper ends are almost sure to be rusted, and they are made of 100% unobtanium, and have been for 30 years. The Super/Roadmaster (senior series) bumper ends are different from the Special/Century (junior series). The exhaust passes thru the bumper ends on the senior cars, along with road debris. They are always found rusted. The last set Art had done that I am aware of were $2000 a copy to have them rebuilt and plated. This car is an early car, witnessed by the "short" temperature gauge. The '57's tended to run warm, since the engine was surrounded by more metal than before. To "fix" the overheating the factory made a gauge that was further from "C" to "H" on the gauge. The engine didn't run cooler, it just took more heat for the gauge to read "hot". This car may also have the short Dynaflow dipstick and fill tube. When you ran the car hard then shut it off, such as in a gas station, transmission fluid would expand and come out the end of the fill tube, right on the hot exhaust manifold. We actually had a '57 convertible we had restored get on fire for that reason. Later '57 and all '58 dipstick tubes will swap and help prevent the issue. The front lower control arms on the '57's are always found cracked and the bolts loose. They made a reinforcement kit, later put into regular production, that kept it from happening.
A well-restored Super, even a four door, is a nice car. One step down from the Roadmaster 73 which was a de-trimmed Roadmaster 75. The Roadmaster 75 only had one option, air conditioning. Everything else available for a 1957 Buick was standard. Art always told me that the Roadmaster 75 had the same carpet as the Cadillac Eldorado Brougham. Arguably the prettiest carpet ever installed in a car. They even put it on the bottom of the doors. The Roadmaster 75 was priced well into Cadillac territory, right under the Fleetwoods.
If that Super is not rusty, a full restoration will run in the 100 grand territory. If Art was doing it, it wouldn't leave the shop without Raven Black two tone under the sweep spear, riding a set of Kelsey-Hayes wires. Paint that baby Laurel Mist or Garnet Red with black under the sweepspear on K-H wires, it would cut a wide swath. Did you miss out on a deal? I'd say you found a good parts car. I'll bet it's rusty....
I'd say you dodged a bullet......
If I had a chance to buy it CHEAP, I would have used it as a parts car for a Roadmaster 75 that didn't have air....

Life can be tough. It can be even tougher if you're stupid.....