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.
As its always risky as buying for third party whom you do not know may end up in a trouble as we are unaware the purpose for which the Btc would be used. So ideally better not to buy as their documents could be fake one as well and end up we being in trouble .