I appreciate the effort to target absolute prices - something I have refused to do… Far more interesting and important is the delta of the competition and their ultimate success in garnering market share.
US third-party payers and EU governments would strongly disagree with your statement that absolute prices are less important than the pricing deltas :- )
In any event, if you have a sales projection for Sovaldi + Ledipasvir (which I presume you do), then you also have an implicit pricing assumption to go along with your volume assumption. Whether you model pricing in the form of an elasticity curve or a simple point estimate, your assumption about pricing is in your model somewhere.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”