Most likely the most important asset of any pistol you carry for self-defence is it goes bang each time you press the trigger if there is a round in the chamber.
My Gen 4 Glock 19 has done that through thousands of rounds.
A used Police purchase will be a decent price (Important area, as in cheap!)
They do not get shot much. Send it into Glock for Glock night sights, $60.00. Good for 4 years, at least. The Glock holster at $15.00? will last forever. And a Glock mag. pouch the same. Spare mag a Glock 17 one.
Watch a few Seal or other Special forces videos and see what carry pistol they recommend, Glock 19s. 16 rounds out of the gate, and accepts 17, and 15 round magazines. Just a thought.