i would pay an extra twenty bucks to have a smartphone with a sapphire screen.
from the motley fool crue article... "Last week, MIT Technology Review published a report on the possible future use of sapphire in smartphone screens, which could potentially replace Gorilla Glass eventually. This threat isn't at all imminent, as the cost differential remains very high, so most smartphone vendors wouldn't yet consider adopting it.
A Gorilla Glass display cover currently costs less than $3, which is much cheaper than the $30 that a similar sapphire display would set an OEM back. Eventually, the cost of sapphire could decline to below $20 due to competition and technological advances."