If ammo cost is a concern, then XDM 5.25 in 9mm. Great
by Cherokee 
, Medina, Ohio, Tuesday, August 14, 2012, 11:26 (4486 days ago)
semi and low cost (relatively) ammo. But a 1911 in 9mm would also be good for low cost ammo. 1911 45 ACP is a great first gun if he can swing the ammo cost.
Ooops, should have been posted below.
I picked up an M&P Compact in 9mm primarily for the cheaper
Ammo. Got a great deal on a used one, which helps but I had a pretty decent carry gun in 40.