The 242 must be that light 7-shot 38 Spl revolver. I have the 296. $500 is on the high side, but hey, as long as you have it, that is all that counts. It is s astout little revolver to shoot. You will need to give it the range time to get the feel for the gun. It is manageable. There may be a limit on the grain weight for the gun. Most light Smiths have that limit to prevent the bullet jumping the crimp from the cartridge and binding up the cylinder to the forcing cone. As long as you limit the +P and weight (158gr?) as prescribed by the manual, you should be fine. When new, those things were around $580. When discontinued, they were being clearanced for around $400.
The main thing to be careful is to not use Flitz or any harsh Scotch brite abrasives around the cylinder face to get rid of the carbon black rings. The Titanium cylinder has a coating which the factory advises against using such abrasives.
I love the humpback revolvers. My 296 is the same size as the 242, except it shoots five 44 Spl rounds instead of seven 38 Spl.
A lot of people like the gun because of the lightweight alloy and Titanium. Shoot factory ammo through it and it should be fine.
If it were "used," you may want to spend $5 at WalMart and get Break Free CLP and some cleaning patches. RUn it through, and it should be fine. Most guns are "Pre-owned" instead of hard "used." People shoot about 50 rds through one, and then decide they do not want something anymore.