I missed the segment, but I have always assumed that the appraisers on Antiques Road Show always come in on the high side, because it makes for better TV. Not inflated -- just generous.

As for tuners, I picked up a "vintage reissue" D-28 (1995) on eBay with them open tuners, and I much prefer the Grovers on my old D-18. I'm thinking of changing over the D-28, authenticity be hanged.