I'm not talking utility theory, I just mean, you can't have free market capitalism without freedom to trade, and trade is the exchange of one thing (usually of money/currency) for goods. Goods have value. It's not necessarily a fixed or absolute value, but there is obviously value there. When I said I was making it simpler, I meant it. I'm not talking any specific theory of values, just that value itself exists. I guess you could call it the Value Theory of Value.

Communists don't even like to acknowledge that, because it hurts the idea of sharing everything equally. If things have value, and take labor to produce, there's incentive to get good deals for it, or otherwise not share the wealth.