Nobody here is going to do better than
Jim March's Revolver Checkout when it comes to what to look for in a used wheelgun. Mr. March sets the standard.
If your prospective gun was a Model 10 or M&P, the $200 price might be a tad high, but OK for a chain store depending on your location. Model 10s and M&Ps average $150 or so where I'm at. I have bought them for under $100. I would walk away at $200.
If the gun was a K38, $200 would be a steal if the condition was good.
So, you see, you have to know what kind of gun it was. A S&W .38sp is just not enough to go on. Open the cylinder, look in the yokespace of the frame for a model number. If present, there's your gun. If not, it is pre-1957. If it's a pre-1957 and in decent shape, it will garner $200+ in most places in the country.
If it has no model number and a half moon front sight with a fixed rear, it's a M&P.
If it has no model number, a ramped front sight with an adjustable rear and a K prefix to the serial, it's a K38.
Those two are the most common. If it falls outside of that, such as a half moon front sight with adjustable rear, buy it anyway. You can find pics of K38s and M&Ps on my site, or on GunBroker.
I will say this, for $200, you will not get shafted for more than $150.
If you can stand that, buy without finding out what you are buying. I've made that gamble before........
Finally.......... Post Pics!