If you are retired, and have an entire season to hunt every day, I would hold off until later if there's another certain buck that you'd rather shoot.

If you're in the same predicament as me, where you have almost no time to hunt, you should shoot him the very second that he comes into range.

Were you to let him go early on, he will probably still be lingering around the same area later. But IMHO, that deer looks delicious. He'd be in a world of trouble if he walked within 30 yards of my stand.