I currently have body armor with me sporting a Second Chance T-15 plate. I got it used and love it. This was built many years ago. It's light, cool and fits me nicely.
It's always okay to support the body armor industry by buying factory new armor but if you are on a tight budget, or not in the law enforcement or military, quality-proven used body armor will do you just fine 98% of the time. Just be very discerning when buying one and make sure the panels are genuine and free of compromising damage. Especially for concealable armor users because your primary protection is really not having the attacker know you are wearing body armor. If your attacker knows you are wearing armor, you will lose a lot of your advantage. So wear it always and keep it low. You never know when you will be glad you did.
Before I forget, I should also mention that body armor with hard trauma plates will provide excellent protection from blunt force trauma in car accidents and collisions (prevents internal injuries). Lots of lives have been saved because of this. I think this is another plus to consider if you like any excuse just to wear one.