There is of course a lot of work on altruism and why humans might be altruistic. Take as an example of a good that may be undersupplied by private markets, skills in analytical thinking. What I was getting at is precisely that what fits into such economic planning mechanisms is not such goods but surrogates for them, even if such goods can be cited quite sincerely as their rationale. Often things are ingeniously created just so that they are amenable to such planning. For instance, one can plan and calculate the number of university places to be made available, but university places are not the same thing as skills in analytical thinking.
Prices are only one way of achieving an allocation of resources.
If exclusion cannot be enforced and goods are non-rival the goods are public goods. Then, adopting a liberal non-totalitarian view of the world, you need to elicit what people's preferences are for supply of such goods. From a liberal standpoint there are various voting and other schemes possible involving the design of truth-revealing mechanisms. It is complex. The reason it is complex is that people may have a propensity to misrepresent their preferences.