I love revolvers but I want to get a good semi automatic. After watching youtube videos about many Glocks I am down to three. Glock 19, 23, or the 21. But which one should I get? The 19 is a great gun and ammo is cheaper between the 3. The 21 a little bit expensive for shooting and the 23 is right in the middle. If anyone can help I would appreciate it. Thanks!