Warning! Wall-o-text inbound!
Prices shouldn't be based on supply and demand. They should be based on the time required to acquire or manufacture something. If a couch can be made with roughly one hour of labor, it should be worth one hour of someone else's labor.As for people not working enough, that's absolutely fine. We really don't need that much production. Not nearly as much as we use. If people want considerable amounts of luxuries though, they will have to work more. Perhaps a certain amount of mandated work for those who are capable to cover food and utility costs, but beyond that, you should get as much out of society as you put in. If people collectively decide they don't want to produce luxuries, there's nothing wrong with that.
The problem I see with this is that if you measure everything in hours you can get some crazy results. I mean are we just counting factory time? Because then I could buy a car for 27-35 hours worth of work then (which even at $50 and hour is only $1750). Are we including growth time? Because then things like a single peach skyrocket up considering that teams of people work long hours for months to grow, tend, pick, and sort a crop of peaches, which even after division by the number of peaches in each crop still leads to a substantial number. Are we including transportation time? Prices go up even more.
And what about jobs that produce more then others in the same amount of time? Who determines the hour ratio that each job functions at? Is an hour of saying "thank you may I take your order" worth the same amount as an hour of working in a clean suit building circuit boards? What about an hour digging ditches for irrigation? If the president works an hour on national security is it worth the same amount as an hour spent picking avocados?
Now even assuming that this whole system works miraculously, somehow all of your prices are normalized, you come up with some sort of multiplication system for hours so that jobs that produce more are worth more, and you still run into one simple problem. What if nobody wants to do a certain job? With supply and demand determining prices, you know that if the demand ever outstrips the supply by far enough, then somebody will start creating that object if only for the fact that they can sell it for immense prices. If the whole thing is based on hours to produce though, then what happens when you have 1,000 people asking for TV's and you only had 500 produced? With an hours system there is no incentive to switch to a job that fulfills that demand, and you end up with 500 people who are unable to spend their hours. Which 500? Who knows! Of course you could always simply adjust your hours multiplier in order to encourage people to produce more of the desired object, but then you are once again allowing demand to moderate your prices, only now you are using it to modify the supply directly through wages. Any hours system leads to a capitalist society the instant you introduce wage manipulation, and if you don't introduce it then you don't produce what you need; since I know for a fact that me and 99% of the people out there would rather do some easy, not very productive job then do hard work that is highly productive.
Yes I am all for a massive work-for-needs program that allows those who can to work in exchange for the necessities of life; and yes, I agree that if we had some massive thing that could react quickly to supply and demand to promote co-operation it would be better, but right now we don't have one of those.Instead we have the one system that currently reacts fast enough to ensure that there is enough supply for those that want and enough demand for those that produce, capitalism. Because face it, at heart people are utterly self-centered and without some sort of positive reinforcement they won't do anything they don't need to. Sure you might point out heroes and those who acted selflessly, but if somebody throws a knife at you, regardless of who you are, your first instinct is going to be to duck, ignoring the fact that there is a child behind you. That's what makes those heroes so amazing, the fact that they overcame that selfishness that the majority of us are bound to.