Model 15's seem to generally be a real good value. As others said, maybe one of Smith's best .38 revolvers. I don't see people getting real big money for them, though. Yes, I see people asking big money, but not necessarily getting it.
My view is buy it if you want one. And if you don't have one, you should want one...if you like target revolvers. Don't, however, buy it thinking you'll make a quick 200 bucks, because you may not. To me, it sounds like a great value more than a great deal, because model 15's are currently undervalued. Too many pawnshops/hunting departments see them as model 10's with adjustable sights, and I'm not sure that's an accurate assessment.
When the vintage gun buying public wises up to model 15's the values will shoot up, in my opinion.