4" or 6" bbl.?
Not that it matters, but the only decent gun I've seen under $200 this past year was a 3&1/2" Charter Pathfinder 22 for $150. I bagged that going out the door from another gun purchase.
The Mark III is not my favorite Colt ( prefer the earlier "357" and "Trooper" ) but it's head and shoulders above ANY S&W made today. Just my humble opinion.
I would make sure that gun either got shot until you dropped, or got stashed away with maybe 500 rounds of factory magnum ammo of your choice.
Ten or more years back I had 10+ 38 spl.s. That's because I bought every gun in good enough shape that I could get for under $150. There is no way you could buy anything that would justify selling that gun. IMHO