Peoples' wants and desires are infinite. As long as there are things to desire, there will be jobs to do.
http://techcrunch.com/2014/06/21/welcome-to-extremistan/
If today you replaced half of the blue-collar jobs in our economy with jobs that had a 10% chance of paying 100x as much but a 90% chance of paying effectively nothing (10x the average productivity, woohoo) you would still have widespread starvation, revolution, and violence tomorrow.
"Incredibly cheap" is not a relevant metric. The relevant quantity is price/income. If income drops by 50% and price drops by 10%, the good has still effectively become almost twice as expensive.
Obviously there is a utopian solution, where most goods and services are so cheap to produce, that most people have essentially free access to them.
What is worrying is the dystopian alternative (and probably inevitable adjustment period), where only a tiny fraction of the population is "valuable", and therefore has access to all the benefits of cheap automation, while the other 90% have no value (economically speaking).
We also tend to forget that we live in a sort of intellectual bubble. Just by being able to hold a highly technical job, you are probably already in the upper 90% percent of the intelligence spectrum. 80% of the world's population has an IQ of under 115; and half the world's population is under 100 and can barely grasp any form of abstract logical thinking.
If the vast majority of jobs in the future require high technical or intellectual aptitude, then the vast majority of the earth's population will be left with nothing to do.
"Consumerism" (which goes beyond "stuff" and materialism, at least here) has been criticized by many in the western world. Even just leaving aside the argument that involves a finite planet sustaining ever-more needs and desires, I'm not convinced that the average human's needs and desires are infinite in any practical sense. It might be that "more is more", but I also suspect a sharp decline due to diminishing returns as one gets ever more needs fulfilled. How much better does spending 1,000 million on yourself feel than spending 100 million on yourself? Significantly better? I guess we could theoretically get to the point where everyone takes what is in today's currency billion-dollars worth of vacations by going on trips 'round the Solar System. But at some point, maybe before we're at the point of the Solar System joyrides, it just might not seem so exciting any more (travelling to the red wasteland of Mars might not be so exotic and exciting as it is today when a lot of people can and have already done it).