I don't think that price is out of line. I have a small track on the 19 snubby:
Smith & Wesson 19 2-1/2 inch barrel. Revolver in .357 Magnum,.38 Special, Plus . Bluebook of Gun Values (33nd Edition) indicates between $325 in 95% condition and $550 in 100% condition for this gun. I have 49 recorded prices for this model gun from $395 to $795 over a period of 5 Yrs 4 Mos ending August 12, 2012. The average price as of that date was $551. No refurbs, no refinishes, regular sights. All represented as 95% or better. No distinction for import location or engineering revision, if any, no special editions, no distinctions for box, papers, tools. Current or last MSRP is $457.
Here's the chart of the data
In spite of my having relatively few price data, the price trend is pretty clear. With box, papers, matching numbers, and all, your gun is clearly at the top of the line for value. The price you paid, in my opinion, is a fair one and given the increasing demand for the model, I doubt you'll lose money should you ever decide to sell it at anytime from now on.
As far as having a "known fault"is concerned, you may wear out or damage a 19 if you shoot a lot of full magnum loads— others may expand on this— but if you're anything like me, shooting a lot of magnums from any snubby is not financially possible nor is it much fun after 30 or 60 rounds. Shooting .38 Special rounds, even plus P, is more tolerable and affordable. Just clean the cylinder bores to get rid of the fouling from the shorter cartridges.