After looking things over I'd revise the royalties downward to $200M (this is likely too small as several items are not disclosed), it looks like there should be an accummulated loss of around $400M, at 35% that's $140M, and accummulating the last five years of R&D exspense ~$200M as the intellectual property value, throw in $75M cash and that's $615. Discount it 50% to $307M, and divide by the outstanding shares 44m, and you $7, if you divide by the float shares ~30m, you get $10. (Note the company went on a stock by back spree so a large number of authorized shares are sitting in the treasury. Why they did this, a ~$10 a share, and how many is not clear, it looks researchable but in any event a significant number of the outstanding shares are held by the company. I'm not an expert in these matters but I believe that portion of the sale value would be distributed to shareholders). A constructive critique of this analysis is welcomed.
Correction: The accummulated loss is more like $150m, or at 35%, worth $52m.
That puts a revised Per Share Valuation Estimate at: $6-$9
Again the use of ~30m float shares accounts for the higher estimate in the three dollar swing. I believe this is in fact the more correct number, but there is uncertainty as to how the some 11-12m repurchased shares will be accounted for in a final sale payout. These shares are termed 'retired' in the 10Ks but they're still in the total tally of 44m registared shares as of March 2013 since the same total number of shares (44m) were registared in March of 2006, before the significant repurchasing occured.