1.) Tbh, I prefer a natural diamond for a variety of reasons. First of all, I think lab grown's are essentially worthless. I can't fathom spending 20k+ for something that holds very little to no value. I know natural diamonds don't hold much either, but at least they're worth something and highly desirable.
Another reason I'm leaning towards natural is because I have seen a coworker's lab grown diamond and it has insane amount of blue nuance. To me, the diamond straight up looks blue. That's definitely not the look I'm aiming for

. To be fair, I've only seen her ring on an airplane with plane lighting, I suppose. I actually don't know what her ring looks like in natural light -- we work
on the airplane so it is likely that it will bug me
every single day.
I've also seen lab grown diamonds IRL when we made an appointment at a Brilliant Earth. I didn't see any blue nuance, but the lighting was so bad that we were literally looking at the diamonds in the shade.
2.) I think he's looking to spend no more than $25k natural or lab grown. It is likely that he'll end up spending nearly the same amount should we decide on lab grown (but it'll be a larger stone with the same specs -- G, VS1 or VVS2, super ideal cut).
3.) I definitely prefer a conflict-free diamond. But how can retailers be sure that they're conflict free if they're sourced from Africa?
4.) I really don't know! To me, 2cts is sufficient for round and oval. My dream shape has
always been a cushion though, and a 2ct cushion looks way smaller than a 2ct round or oval. All in all, the blue nuance bothers me just as much as a 2ct cushion. But the blue nuance might bother me a bit more lolol
Thanks so much for your well thought response