The one-of-one Callaway Sledgehammer C4 Corvette was built to do two things — crack 250 mph, and not fall apart in the process. John Lingenfelter blasted past that objective on October 26, 1988, reaching 254.76 mph. Then the car sat in museums for about three decades. Now it’s up for sale.

At the time of writing there are nine days left before the Sledgehammer goes to the highest bidder over at . The current bid stands at $425,476, and while the says it was sold once, in 2004, the buyer was none other than founder Reeves Callaway himself.

Thus, the Sledgehammer is in immaculate shape as you’d expect, with Callaway Cars having serviced the engine with new couplings, hoses and fittings in 2018, and the odometer reading just north of 2,000 miles.

The Sledgehammer churned out 880 horsepower and 772 pound-feet of torque from its 5.7-liter twin-turbocharged V8. But to break 250, it couldn’t just be powerful, so Callaway comprehensively redesigned the exterior to reduce drag and optimize cooling. The suspension was tweaked too, with beefed up shocks and a lower ride height. Of course, a rollcage had to be installed as well — and these only comprise some of the most notable changes to this legendary Corvette.

In the end, the Sledgehammer accomplished what it set out to do. Callaway intended to keep developing the project and enter it in various media competitions to determine the fastest cars in the world, like Car and Driver’s “Gathering Of The Eagles” that originally inspired the build. But after that momentous 254-mph run, the Sledgehammer pretty much sat dormant.

Callaway has of course continued making wild Corvettes since, , which for the GT2 class at the 2001 24 Hours of Le Mans. (not to be confused with the C7-generation Corvette, mind) that is my personal favorite, since I had a Hot Wheels of it as a kid growing up and it was featured in Project Gotham Racing 3 on the Xbox 360.

One of Callaway’s coolest creations also happens to be one of its most recent: the from 2017. Because everything’s better as a shooting brake — even a ’Vette.

Back when it built the Sledgehammer, Callaway pegged that it would have cost $400,000 — in 1988 money, I emphasize — to put in series production. That translates to about $902,000 today. Right now, with the car sitting at just about half that and more than a week left to go, I have a hunch the Sledgehammer will reap what it deserves and then some.