re: Cousin just asked me for money: he’s a high income earner and parents are wealthy

No idea how close you two are as friends,other than just being family, but fully expect that if you lend someone that substantial amount of money, you not only will not likely see it ever returned, you also will lose a friend.
He will ghost you once he gets the cash.
And if you dare ask for anything back he'll just get argumentative about your asking.