Trade-Ins are the way to go, meat - - -
---as mentioned earlier by Jim Keenan.
An amazing number of police and security service personnel care little or nothing about shooting, and fire their issue sidarms only during required qualifications. It is possible to buy a high quality revolver for a very reasonable price. The "condition" determines the price, most of the time. And a certain amount of bluing wear is truly no detriment to good functioning. If there are no deep dings or dents and the cylinder locks up tightly and the action feels pretty crisp, chances are the the used revolver will be a good value. If you are inexperienced with revolvers to the point of wanting advice, you probably know someone who'd be happy to look over an anticipated purchase.
Suggest you don't pay a big premium to get a magnum as opposed to a .38 Spl, given your stated purpose. A great many people prefer to use .38 loads in their mags for home defense, anyhow. Reasons include lessened chance of overpenetration, reduced muzzle blast, flash, and recoil. Training time to proficiency is also reduced, and good factory .38 ammo is somewhat less expensive.
The majority of these used revolvers are four-inch, unless you find some investigations division guns that were traded in. Four-inch is NO handicap, especially if the arm is to be used primarily for home defense. The longer barrel makes for easier pointing in the dark. Some say the longer barrel makes it easier for a goblin to disarm the user, but I think this danger is overstated. Also, if concealed carry is a factor, with a holster, the longer barrel presses against the hip and holds the grip area closer to the body. The two-inch barrel is really only a factor when carrying in a pocket or ankle holster.
Best wishes on your quest.
Johnny
PS to Jim Keenan. Noticed it was your FIVE THOUSANDTH post. I stand in awe.
JPG