Not sure on when, but as to value, not really as say a Dog Father will always be worth what a Dog Father is worth, as from what I can see Scrap Yard never made the same model out of both SR77 and 101. Some may well prefer the SR77 blade, sure but if this is the factor that drives up the price, I don't think so entirely (a factor perhaps), in this case it will be more about that particular model and the desirability of such. Had they made say Dog Fathers in BOTH SR77 and 101 then there may be more of a price influence from the steel as you are able to cost apples against apples so to speak.
And ignore Bravado, he has just been cranky since he was neutered.
Andy