ive heard that the problem with the fingerprint scanner is that the screen is getting brighter on the spot where the scanner is fixed so for an idea you can make a little amoled screen under the home button in the budget phones like the A series for an example to show notifications while phone is on this way you can have an always-on display without the need of a full amoled screen its just a little screen under the button and the main screen can be a standard LCD this will lower the price i guess and even if the screen is brighter its no problem since the scanner will be the whole screen so if its all bright it wont look ridiculous.
