The money invested in new firearm goes well beyond the cost of the gun itself. There's always a variety of holsters to buy, magazine carriers, extra magazines, and of course copious rounds of practice and self-defense ammunition to verify the operation of the weapon. Since I am anticipating the purchase of a SIG P365 at some point in the not-too-distant future, I've been "pre-loading" some of those supplies. The calendar in spring and summer is also full of holidays when many suppliers offer sales, so I've been taking advantage of those as well.
No one waits until the baby arrives to begin preparing the nursery, right?
Still to be added; belt magazine carrier, extra magazines... And the gun.