I have purchased multiple drones from this Korean seller with no issues.
https://www.ebay.com/str/gswholesale
I have also heard about multiple positive experiences with these
https://www.ebay.com/str/102store00...
The extra physical buttons/controls are what appeal to me the most. Being able to change more than one camera setting without having to mess with the touch screen must be nice.
The Mavic and Air series aren't super cheap. If this is his first drone and he's looking to save money then steer him towards the DJI Mini 4k. Its not the top of the line, but it can still get some great cinematic photos and videos.