Begs the question though, what exactly are they doing during R&D?
About 2 years ago i was building comparable devices for around £285 GBP each. Today i can do the same (thanks to cheaper lighter parts and experience on my part) for slightly over £110, that could be reduced for bulk builds.
My R&D costs were 2 weeks worth of my evenings reading and planning.
You can buy a commercially developed equivalent with better flight stability than the model they've produced (their design is inherently more unstable - and thus agile, and possibly slightly quieter) for under £60 delivered, video reception equipment is a separate purchase at £30.