Price are a signal, but they only move at the speed of the market, with modern information technology it is possible to know the precise stocks in the warehouse before market activity occurs. The lag between real and price signals is one of the reasons for modern economic crises.
You know you need a hammer when you have to bash nails into something. That does not require monetary calculation. Consumer goods do not need monetary calculation; the issue is intermediate goods (does making the chair need a hammer, or could I bash the nails in with the sole of my shoe?). The argument runs that we can’t know, without money how to produce those consumer goods. There are various counter arguments:
[ul]
[li]It doesn’t matter, so long as the ends are met.[/li][li]In a relatively stable economy we would be able to know what the regular requirements of the whole system are.[/li][li]Abundance of supply removes the need to make calculation arguments.[/li][/ul]
[ol]
[li]Local communities and individuals would decide their own needs, and place orders for goods.[/li][li]As goods left the common store, they would be replaced to match demand.[/li][li]That would provide a signal for the intermediate parts.[/li][li]This would be handled by statsitical clearing houses that aggregate demand in relation to total supply—that is, supply and demand would be known absolute features.[/li][/ol]
This is regulated stock control. The community as a whole (worldwide) may decide to set priorities so that certain goods get first claim on resources, but the aim would be to match total real demand. Given supply and demand are known, we can economise (and substitute) those goods which are least available and have highest demand.
The Soviet Union did have prices, and wages, and markets (black and otherwise). The collapse of state capitalism in the USSR was down to its difficulties in the intensive exploitation of capital (similar to the issues involved in the Asian Tiger crisis ten years ago).