It is hardly a revelation that productivity increases in services are less easy to come by than in goods. But how can you honestly say that cheaper goods do not increase the basket of consumer goods people can buy. You say Cox and Alm's research is shoddy (which would appear to be a euphemism for Texan if I read you right). But you do not say it is wrong. If it is wrong, perhaps you could explain why. Perhaps you could show that there have been no productivity increases in telegraphy, agriculture, and so on? That would be interesting indeed.
I really do not know why you are so resistant to what is plainly the case. People buy more stuff than their parents did, and much more than their grandparents did. Certainly they buy iPods, personal computers, broadband, and all kinds of consumer goods that were simply not available to their grandparents. And they spend much less on basics, which are very much cheaper.
There are interruptions to the trend. Enduring recessions, such as in the early eighties, 1930s disrupt the underlying movement, but the long term trend is there for anyone who is not determined to lie about it.
And what is more, it is precisely the trend that Marx anticipates in his theory of capital accumulation. Indeed, if there were no tendency to productivity increases, and the concomitant spreading of the wage over a greater sum of goods, there would be no capital accumulation in Marx's theory.
More to the point these changes