7 year olds are right between using dedicated kid gloves and that middle ground of more serious gloves with small hand stalls. Used gloves are likely to be stretched out and broken in to someone else's (probably larger) hand. Unless someone has a nwt glove for you, I think you are better off with a new one. Assuming he has a normal size 7 year old hand, a Rawlings R9 Series 11" or 11.25" is what I'd be looking at. Or maybe the Rawlings narrow fit GG Gamer 11.5" G314-2B. The Brett Bros ML2-1125 also looks like a solid kid glove.