Many of us here watched the "restoration" of these cars as documented on the American automotive show, "Fast and Loud". Those of us familiar with that particular show cringed through the filmed process knowing that their primary business plan is to "flip" cars as fast as possible for as much profit as possible against fake deadlines. We would have much preferred that these two cars be restored by another firm where minimizing time and expense were NOT their prime motivation.
We can probably guess that the people that pay out for these cars are finding out that the "restorations" were indeed shoddy and they are being passed from from collection to collection like bad pennies.
I believe the $30K price you have seen from 2012 was the price the original owner picked them up for before he sold them to Richard Rawlings from Gas Monkey Garage for the TV show.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI