"...The per disc cost of BD-ROM DL is approximately 15 cents more than the HD DVD DL cost...."
Wholesale, from this link. So if we take your five fold increase, wholesale to retail, that's 75 cents per disc.
From a link that is very unsubstantiated. Until it's validated it's nice reading material. Other reports have the price differential at the $1.00/disc number I was quoting.
Or looked at another way, as in my 2/12/07 post above, we're spreading out the increased cost of the BD replication plant at about a dime a disc.
Perhaps. But that remains to be seen. What will happen when the subsidies end?
When Sony stopped subsidizing SA-CDs for several major record labels they ceased production of new SA-CD titles. I don't think that will happen for Blu-ray but it might negatively impact the title cost.
Plus, from a purely manufacturing cost, the BD disc could be cheaper than HD-DVD, not considering the plant. One plastic layer, not two. Less alignment/glueing. Spray on a coating. Costs will come down anyway, as they gain economies of scale and learn new techniques. My point is, the mantra that HD-DVD is so much cheaper is a weak argument. It isn't, not in the long run, not significantly.
You can't divorce the cost of the plant from the overall delivered product. You can amortize it over a huge amount of discs but that's it.
Cheers,