You can buy any aircraft from other companies but they don't have the technology that DJI possess in getting extremely long range in their aircrafts. The Typhoon H for example, cost the same or more than a Mavic pro but it has the same range of a phantom 3 standard.
Perhaps, but the TH has several features the Phantom does not have such as retractable landing gear, you can pan the camera, 6 motors allows it to switch to five motor mode to keep it airborne long enough to land, and with the wizard allows two person control (one controlling the camera, one controlling the aircraft). More importantly it does NOT have GeoFencing. Features you have to buy the much more expensive Inspire ($1999) for.
The Mavic is listed at $999, the TH is also $999, and the TH Pro at $1499 at Best Buy. Looking at the specs it looks like the only difference between TH and TH Pro is better object avoidance.
As far distance goes I loose the video at the same distance with the P3S as I do the P3P.
As I mentioned in my previous post, if the airport and hospital (MedStar) say it is OK to fly who is DJI to say I can't.