i have a iphone 4 16gb

so this is my mobile problem..

1. When i plug my phone to the power cable (charging but not cable to computer) i can switch on my iphone. and when after i pull the usb cable off, the phone wont start again. i go to the mines 1 , that guy try to replace a new battery but still wont work.

2. wifi greyout ( wifi show NO WIFI , mac address N/A)

3. Home button not sensitive and hard to press

4. Microphone problem
when im calling my friends, i have to put in loudspeaker mode . if i put to normal mode, the person that i calling cant listen any voice from me.

For my situations, i wanna ask for the price to fix this phone. thx you and hope reply from u soon.