My elementary-school-aged daughter keeps asking for a drone, and although I'm dubious about whether she's old enough I'm thinking of giving her one for her birthday. Neither she nor I have ever flown one before, so one of those cheap (~$50?) mostly-indoor slow ones with a prop guard would be appropriate.
However, there is one thing I'm picky about that makes it hard to just look at some reviews or pick one randomly from Amazon: I have a pretty strict policy of avoiding proprietary software, so having it use some sketchy smartphone app for the video feed (or anything else) is a deal-breaker. Having the firmware on the drone itself be open source is almost as important. (I'm not sure, but I get the impression that most of the non-DJI no-name and FPV racing type ones are? The drone youtube videos I've been watching mention Betaflight a lot, and seem to assume that pretty much any drone supports it.)
I would also very much prefer it to use "standard"/popular communications protocols (ELRS and analog video if I get something with an FPV camera...?).
Finally, I'm not afraid of 3D-printing the frame and soldering together the components myself, especially if it could result in a significantly better drone for the money. However, I am intimidated by the notion of sourcing components that work together properly, so if somebody could just spoon-feed me a BOM that'd be great.
Suggestions?