View <=>ViewModel<=>Model
Formatting display for a View is the responsibility of its ViewModel.
I will argue for each View there should be one and only one ViewModel.
In this way, your business object, as a property within both ViewModels, can supply the list and each ViewModel can then format the data specifically for its View in the propety getter. You should be able to format much display in the View xaml binding expressions... e.g. 'StringFormat="C"'...
I believe it is a mistake to use ViewModels as business objects instead of using ViewModels to simply resurface Models for consumption by Views. I prefer business objects that work locally to orchestrate Models so that they are cogent and testable; they are not a part of the EF schema. This business object API that orchestrates logic upon the Models is produced from Test-First Design, in the best case scenario. ViewModels are for the single purpose of providing formatted display for binding to the View.
Here is a link you might use http://visualstudiomagazine.com/articles/2011/10/01/mvvm-in-5-minutes.aspx
