If by this you mean that standard supply-demand economics can't model price discrimination, which is what's going on here, that's not correct. See, for example, Chapter 10 of David Friedman's Price Theory, where he models price discrimination using supply and demand curves just fine. In terms of this kind of analysis, price discrimination is a way for sellers to try to transfer as much as possible of what would otherwise be consumer surplus, to themselves.

You decide if a price is worth it to you. The LSD is just an aggregation of that.