No i wouldnt but it wouldnt stop me buying a iPhone, or any internet enable phone either. Have safe user practices and you should be ok.
If this is really what you are worried about, my suggestion to you is dont buy a phone what so ever, (there are listening devices out there as well) dont get on the internet, close the windows of your house, lock the door and say goodbye to the world as you know it.
Sorry if this seems harsh, but you know how insecure the net is these days, you know it can be done on a PC. Heck i can remotely use my Mac.
If you have safe practices, as in safe web browsing, safe email reading, you dont dl anything suspicious, you dont install things you are not sure of, you dont put in your password if you are not sure why you are then you should be fine to buy a iPhone. What i just mentioned, if you are safe in all of those and more then *someone* has no way ever from being able to do that to you .... IMO anyways
Cheers