No ... you don't have to build your own quad if you don't want to. You buy a so called "Bind & Fly" which is pre-built and includes FPV camera & receiver... but no radio, no
goggles, no charger & no batteries.
But a warning is in it's place here ... you will not get cheaper off going the FPV quad route compared to a
Mini 1 you have posted about earlier... that is, if you don't have any earlier needed equipment that you can reuse, such as radios,
goggles, batteries & chargers.
Going all new into a DJI digital quad you easily ends up with a cost up to 1300£ ... it's approx equal if you go for a analog system with a equal quality level. Sure you can go with a analog indoor Cinewhoop kit for much less... but that isn't comparable with the cheapest DJI GPS camera drone.
Furthermore the learning curve to master a quad is much steeper then with a GPS stabilized camera drone ... recon you need 20-50h in a simulator in order to not crash it immediately. Then when it comes to footage & stills ... with the
DJI FPV system you can get some 720-1080P footage in acceptable (show grandma all the fancy moves...) quality from the liveview, need more you must add cameras like a GoPro. Stills is not feasible.
You have a bit of FPV & Bind & Fly discussions here in relation the rumored
DJI FPV kit quad (which will not be cheap when they launch it) -->
DJI FPV Combo 2021 Rumors? Where is it? and
DJI FPV Combo 2021 Rumors? Where is it?