I'll echo everyone else in saying you didn't overpay ,and I'll also add that the nice thing about a model 19 is that you'll always be able to get your money out of it. They are among the most desirable of the old Smiths (after gems like the registered magnum, model 28, .38-44 and some other rare variants), not being made any more, and prices on them seem to keep going up and up. I got my 95-97ish% condition 8 years ago for $295, and overpaid at the time. These days, you'd think I was robbing someone if they sold that gun to me at that price.
That 19 is going ot be a great shooter for you! I just hope you can find some .38spl target ammo for less than $21/box. It seems .38 prices have gone nuts recently.