i just recently purchased a used Phantom 2 vison with no Camera and no  wifi repeater, which fine becasue i have my own gimbal and Gopro camera. However, my concern is the following...im laready getting a live wifi feed from my gopro camera, does my drone itself have a wifi signal that i can bind to the DJI vision on my mobile device so that i can use the radar/altimeter/battery life functions?(these really matter to me )  any help with this would be greatly appreciated
thanks!

For the Vision app to work you will need to buy a Vision camera and Wi-Fi range extender, without them all you have is a bare bones Phantom 2.

Can you say what you paid for it?

it had bent the plastic shell beyond repair and he didnt want to invest the time in repairing. he bought a new phantom. so i offered him $150 and he accepted. i bought a new shell online and rebuilt it. he kept the wifi repeater and the vision camera.

Hi, actually you do not need to buy a DJI cam.
What I did, being in more or less the same situation as you are, is buying a cheap ($ 35) gimball, a pinhole cam and connected the gimball cable to the wifi module in the phantom. On the phantom otherboard there is a camera connector. To this connector you can feed an analogue video signal (PAL works, NTSC might worl, I do not know). The video feed will be compressed by the wifi module and an overlay will be added  by the wifi module.

Your gimball probably has common 'servo' inputs. These can be connected directly to the naza controller x1/x2 outputs.

Following this scheme with an original phantom 2 vision +, you will be able to control the pitch from your smartphone app and will recieve the 'default'dji picture, including overlay on your smartphone. Of course you will not be able to control the expensive or dirt cheap additional camera that you will mount on the gimball. But I have yet to see the cam + sd card that will not grossly outlast the battery time of a quadcopter. Just press record and start to fly. I have never seen the use of switching the cam on and off in mid air.
Why is thi sso cheap?

- A cam that can record nice movies with high resolution AND output a liive signal for the wifi module is VERY expensive. (GoPro models with analogue output start from 450 euro's here in holland, other models do not even have analogue output)
A cheap cam (chinese crap cam with HD record possibilities) perfroms just as goos, the only thing you need to add is a 10 euro pinhole cam for the abalogue signal.

- You should, in your case, buy a wifi repeater. Second hand market value around 50 euro's/
So summing it up:

50 euro wifi repeater
10 euro pinhole com
40 euro dirt cheap chinese gopro cllone
7 euro sd card
40 euro chinese gimball.

some googling on the electrical layout, one change in the dji phantom setting (set  advanced/gimball/automatic gain setting -> 0 for both axies)

that's it.
same picture recorded as gopro, good enough fpv (less lag!!)

Hi, actually you do not need to buy a DJI cam.
What I did, being in more or less the same situation as you are, is buying a cheap ($ 35) gimball, a pinhole cam and connected the gimball cable to the wifi module in the phantom. On the phantom otherboard there is a camera connector. To this connector you can feed an analogue video signal (PAL works, NTSC might worl, I do not know). The video feed will be compressed by the wifi module and an overlay will be added  by the wifi module.

Your gimball probably has common 'servo' inputs. These can be connected directly to the naza controller x1/x2 outputs.

Following this scheme with an original phantom 2 vision +, you will be able to control the pitch from your smartphone app and will recieve the 'default'dji picture, including overlay on your smartphone. Of course you will not be able to control the expensive or dirt cheap additional camera that you will mount on the gimball. But I have yet to see the cam + sd card that will not grossly outlast the battery time of a quadcopter. Just press record and start to fly. I have never seen the use of switching the cam on and off in mid air.
Why is thi sso cheap?

- A cam that can record nice movies with high resolution AND output a liive signal for the wifi module is VERY expensive. (GoPro models with analogue output start from 450 euro's here in holland, other models do not even have analogue output)
A cheap cam (chinese crap cam with HD record possibilities) perfroms just as goos, the only thing you need to add is a 10 euro pinhole cam for the abalogue signal.

- You should, in your case, buy a wifi repeater. Second hand market value around 50 euro's/
So summing it up:

50 euro wifi repeater
10 euro pinhole com
40 euro dirt cheap chinese gopro cllone
7 euro sd card
40 euro chinese gimball.

some googling on the electrical layout, one change in the dji phantom setting (set  advanced/gimball/automatic gain setting -> 0 for both axies)

that's it.
same picture recorded as gopro, good enough fpv (less lag!!)