Yes. Buy it.
1. It's a bit high (unless it is NIB). If private party sale, offer $325 and go from there. If from a shop, see if dealer will go down 10% ($360). Or offer full price for weapon and see if he'll throw in a box or two of ammo, or speedloaders, etc..
2. IMHO, the 65/65LS is one of the most cleanly designed .357s ever made. Form, Function, Shootability...all outstanding.
3. S&W will shortly quit making the K-frame .357s. They will only increase in price over the years.
4. Even if you pay full price (plus tax), you've still have a great revolver and will forget the minor tariff over the next few years of enjoyment. At $399, I doubt that it will sit there much longer...