sminlal :
The gas companies and airline industries had other problems (and the airline industry HAS kept prices very low by cutting service to the bone). If the hard drive manufacturers had wanted to restrict supply they could have done it long before the floods.
The flood of Thai come with the cut of number of HDD producers, there are left now only three : Western Digital, Seagate and Toshiba.
They have only 1 supplier for motors and plates, Nidec, also affected by Thai flood. Nidec announced to cut dependence of Thai production.
Hope that prices for hard drive will be not a problem in the future.