Yeah, I am in Tacoma and shoot at Bullseye when I go. If you ever see a kid with a ON3P hoody there, it is a safe bet that it is me. Sometimes we just go up into the woods, but that is when we are shooting rifles and shotguns.
You are right that .45 gets expensive to shoot though, and I guess considering that, a 9mm would be ideal for him.
The XD45 is appealing to me because it is such a good defense weapon, but in reality, I know that before I got the .45 for defense I would get a Mossberg 590 first. So in that sense, I would probably pick up a 9mm for range practice too. Which would likely be the XD as well.
The weight of the fully loaded XD45 never bothered me too much, but I doubt I would conceal carry with it. Maybe something like the XD compact.
I think with one of the XD (I think the 45) you can also get a 10 round magazine that shortens the grip and would make it lighter, so maybe that would be a better carrying option.
I think the best way for the kid to find what he likes is to go to a range, handle some guns, shoot some guns, and see what fits him the best.
That is sort of what I have done. A lot of people have recommended the glock to me, but I just didn't like shooting it, so it won't be considered by me.