I am deeply puzzled by the question how to interpret the application of the buck-passing account of value to the claim that well-being is a transparent good. Here I try to give my own understanding of it. Please leave your own opinion or correction if you have one.
Scanlon's account of what it means for something to be valuable (the famous or infamous buck-passing account) is the following one:
“being good, or valuable, is not a property that itself provides a reason to respond to a thing in certain ways. Rather, to be good or valuable is to have other properties that constitute such reasons” (1998: 97)
Scanlon therefore should claim that well-being is something valuable, in so far as it has some properties that provide people with reasons to respond to it in certain ways. For example, my well-being has to property of being constituted by my playing tennis and my spending time with my girlfriend. Playing tennis and spending time with my girlfriend have the additional property of being enjoyable, which provides me with reasons to spend time with my girlfriend and to play tennis; since my well-being is constituted by these activities these count also as reasons to promote my well-being.“It is certainly true that we have reasons, in everyday decisions about what to do, to aim at things that contribute directly to our well-being intuitively understood”, as he writes (1998: 126). Hence well-being has the further property of “being constituted by states and activities which provide me with reasons to promote it”, and is therefore valuable.
What Scanlon denies is the “importance of the concept of well-being in [any] given mode of thinking” (1998:126). In the mode of thinking of an agent who is trying to decide how to live the concept of well-being is transparent [an idea I present in this post], i.e. the fact that something contributes to my well-being does not give me a reason to desire it or value it. In a more general formulation, the fact “that X results into an increase of p's well-being” cannot be considered in p's perspective as a reason to pursue X. Hence transparency entails well-being has no further properties, besides the properties of the goods that make it up, that can provide people with reasons to respond to it in certain ways. Transparency does not entail that well-being has no properties providing people with reasons to respond to it in certain ways. Well-being is therefore good and valuable, even if transparent.