For practical usage I pick Model 60. Have one, and wouldn't trade it for any other .22 LR. I did some trigger work on the gun, and now it is just the cats meow.
$140 for the Marlin Model 60
$40-$100 depending for the scope
That leaves $150 or so for ammo. And at $16.00 per 500 you could get close to 5000 rounds of Winchester Xpert (what my Mod 60 shoots best with as far as big box .22 LR), and that would last a long, long time.
The accuracy for a Model 60 @50 yards is untouched IMO for out of the box accuracy with cheap ammo. To be honest. You could leave the scope off the gun for a light weight .22LR that will be very accurate with a 14 year old's eyes. Sometimes I take the scope off my Model 60 because it is like carrying a walking stick. It is light, and is easy to shoot quick.
Marlin Model 60 is my vote on a serious note, but let him pick, and also look a few of whatever gun he chooses. I look at every gun of the model the store has before I make a choice. Some just look and feel better than others.