Your are talking about the science and practice of Photogrammetry. And you can absolutely do everything in the above video with a P3 and some 3rd party software.
You need a 3rd party app like Pix4dcapture, DJI Map Pilot, Altizure or DroneDeploy to fly the automated survey grid. Then, you need to use PC based software (Pix4dMapper, Agisoft) or a cloud software service (DroneDeploy, MapsMadeEasy. Altizure) to process the images into orthographs, DEMs, and/or 3D models. The front end apps to fly the missions are free to cheap.
The data analysis software is not cheap. The professional stuff (Pix4dMapper, Agisoft) are in the $350/mo or $3500/yr range (this is about the same price as the 3DR/Autodesk Site Scan system you referenced above). There are trial or limited versions that you can try, but any professional grade output requires full versions.
The consumer/prosumer cloud based services (MapsMadeEasy, DroneDeploy, Altizure) are much cheaper ($99/mo, maybe less, and generally also have free trials), but do not have the flexibility, accuracy and range of outputs that a professional system has.
It's going to come down to what your goals for the "site scan" are.
