The important thing to consider is unlike many consumer goods, firearms don't generally wear out or get superseded by models with significant improvements every few years. Firearms innovation has really plateaued, there aren't many new "must have" features being introduced each year. Unlike your cell phone a 4 year old revolver is just as good as one fresh off the assembly line and because of that guns tend to hold their value pretty well.
|S&W stock is an investment|
|S&W guns, not so much|
Quality firearms can cost a fair bit of money. If you buy smart and pick products from a quality manufacturer they will hold their value pretty well. As mentioned many used guns have life spans in the tens of thousands of rounds and are very unlikely to receive significant wear by most owners. Find a gently used firearm at a reasonable price and it will hold it's value very well over time. More so, if you find a good deal on a used gun and you later decide it's not a good choice for your purpose you will be able to get much of your money back out of it in trade. Many small shops will gladly take guns back in on trade, often at a pretty reasonable price.
I'm not suggesting buying guns speculatively as a money making deal. Not only is it often a bad risk, but buying and selling guns for a profit falls under the category of dealing in firearms according to the BATFE. Dealing in firearms without a Federal Firearms License isn't something you want to do.
The main purpose of this post is suggest that one shouldn't balk at buying a gun. Obviously you don't want to spend food or rent money on a gun but neither should you stay awake at night because you've spent $400 on one. Guns are exceedingly durable and they will hold their value well over time. Should you be unfortunate enough need one the money spent on it will have been worth it, no matter how expensive it was.