There are already mobiles available from reliance which cost around 800 bucks (777, if i remember correctly). These are full fledged phones with screen, phonebook, alarm, etc. Also, motorola and nokia has gsm sets starting from 1200 bucks. If one wants an even cheaper deal, one can go for a second hand set which are now sold dime a dozen. Can't see why anybody would want to purchase this "blind" mobile without a display.
