Yes, for as long as you pay all the applicable taxes. Make sure you document everything, including the transfer of coins to them in case they try to do anything shady because they'll likely be traced back to you.
This should not be used for other people because it is very risky, it might be better to tell how to buy and maybe we can accompany the purchase, this is to keep all the bad things from happening, because this is related to a very large amount of money.