The 1971 was really an enigma to me. There was a lot of little things on it that I wasn't a fan of. I managed to find a brochure for the 71 Monte Carlo and the 4-speed was not listed as an available option on the 454... Yeah a lot of things did not line up on that car. I'll update the story to reflect that finding on the transmission.
One note: All 2013 Corvettes had 60th anniversary badges on front and rear, the door sills and the convertible waterfall. The 427 Collector Edition convertible was available in all 2013 Corvette colors. Mine was Cyber Gray over Ebony/Red. Z06 drive train and body style, but it was determined that the aluminum Z06 chassis would flex too much, so it was built on the steel Grand Sport convertible chassis. According to GM lit, RPO Z25, the 60th Anniversary Design Package, was an option for any 2013 Corvette, but I have never seen it on anything other than the 427 Collector Edition, which is what the Mecum car was. And Z30 60th Anniversary Stripe Package was an option on cars with Z25, also on the Mecum car. Z25 cars without Z30 are far more rare.
@Rockem Yes, we are very careful to use resources and data other than auctions. Hagerty's Automotive Intelligence team has has probably spent more time at live auctions than the average person. We know what happens in the heat of the moment, especially when the drinks are free. At no point was it mentioned that the Hagerty Price Guide would for sure be moving values because of these sales. These warrant investigation though. Unless there is other data to back up these sales, it is best to assume them to be outliers.
I think it all depends on what you want. A 69 GTO is a big step, but an 04 GTO can be reliably had for under $20K. Keep in mind though, strong sales don't instantly set the market. Continuous strong sales do. These could be the start of something or a flash in the pan.