LOL, of course the salesman is gonna say "yeah yeah, good for interviews", what did you expect him to say? "NO!!! Stop! Don't buy it!" Hahha.
Just busting your chops. Looks like a nice suit, stylish. I'd say it's perfectly fine as well.
As for tie, it depends on your shirt as well. If you wanna bother, you can take some pix for us to judge. I consider myself to be aesthetically-gifted somewhat hehe.