That's true, but if you're operating on-site that far away you'd need an FPV receiver.
Granted I'm coming from a position of privilege, so when I price this in my head I think "$200 for a RadioMaster TX16S, $600 for a Skyline 04X".
You could totally use a much cheaper setup and have it work just fine. For video feed, you can get COTS solutions for ~$50. You could probably build it for $30.
Yeah, if you want the good stuff, you'll spend a lot of money, but a TX16S is way overkill for what they're doing. Plus, if you're going to spend $600 on goggles, might as well get digital ones :P