Just to echo what others have said...while the gift is certainly thoughtful, your friend the JO probably won't want to worry about his nice personal binos...and then when he gets back and you're all like "So, did the binos I gave you help you kill many Taliban?!"....and they've been resting safely in his foot locker in storage back in the states.... you'll save him an awkward moment.
The other risk is that his Marines will think he's a douche.
But seriously...if he needs optics, he's almost certainly got a bunch of dudes around him who can tell him what's up, and at least a couple somethings (optic, laser) on his rifle or RTO's weapon that he can use to confirm...whatever he's looking at. I don't know anything about Marine rifle MTOE, but he's probably got all kinds of thermals/NVD/optics (or all 3 in one package! LRAS3 with far-target locate button, FTMFW!) that he can use, and far better than binos.
LT's greatest weapon is his radio, most important task is to be able to see and understand the big picture, with which to make sound decisions quickly.
So, now that ARF has saved your mega-bucks, just find out what his APO is, and find out ways to send cigarettes, energy drinks, dip, and porno to his guys. Then they'll really want to fight for him.