Honestly, I\'d say a little of Scott and Chris\' explanations. In 1974, your average contestant was Helen Housewife, who could really use that Amana range/microwave/dishwasher. Fast forward 25 years and the average contestant is Charlie Co-Ed, who has no use for the appliances, but loves sneaking in a good \"420\" bid for lulz. That\'s not to say the current crop doesn\'t need the appliances, but it is less of a luxury. Scott\'s comparison to prices makes sense too, in that in 1974 winning a range was a big deal ($1000 then was worth about 4.5x that now). Today, it\'s nice but also not as expensive.
I only watch the show when I\'m on a coffee break, but from what I\'ve noticed, your contestants are either college students or grandparents, neither of which really care about appliances or verandas. So for that reason, I do credit the staff for going after more conventional prizes...I know they still give away hot tubs and porch swings, but seeing more stuff like iGadgets and such is pretty cool, even if they do refer to it as a generic \"smartphone\" or \"tablet\" when Stevie Wonder can see it\'s an iPhone or Note.
To the point of more college students appearing on the show, could that be because more women were entering the workforce by the late-70s, and thus not as many housewives? Granted, that doesn\'t explain the punny T-shirts or hot tubs still being offered, and I know wanting a younger demographic is also partly to blame, but it\'s a thought.