The Austrian school holds that all economic value is subjective. Since economic value is subjective, i.e., in the mind of the subject, all we need to know to do objective economic analysis is that someone values something. The way human beings express that they value something is that they seek to acquire it, either through some type of original appropriation or through exchange. So properly observing human action is what gives us an objective view of what people subjectively value.  That's all we need.

Note that this approach to economic value is merely methodologically subjective. It is not an attempt to philosophically deny objective value, rather it is simply seeking to explain human action as it pertains to the field of economics.

Economics is a narrow discipline while exploring the notion of value in general is a wider philosophical endeavor. Not understanding this is what leads people into endlessly arguing the semantics of every conceivable notion of value. We do not need to go there. The use of the term "intrinsic value" leads us away from the narrow field of economics because it strongly implies a philosophical worldview where objects are constitutionally endowed with value in themselves apart from the human subject who values them. While this may be appropriate in another context, it doesn't help us within the discipline of economics.

That many people, including Peter Schiff, will use this term at times to refer to market or exchange value should be viewed merely as the use of a colloquialism. It simply fails as a technical term to describe economic value because people routinely misunderstand and misapply it when it's taken that way, and so go far afield of the narrow purpose of economic inquiry. You only need to search this forum for "intrinsic value" to see how useless and distracting the term can be. Language is supposed to help us clarify thought. So if a term produces more heat than light in a given context, then it's not working for us and we should abandon it.