[He laughs.] Oh well, you know, that's very tempting! But yes, there'll be a lot more than just the tie. Starched shirt, tailored suit - and you can even have proper shiny black shoes, unlike the Doctor, who seems to wear his Converses with absolutely everything!
[Leading her into the shop and heading confidently over to a rack of jackets, flipping through them until he finds one he thinks will be the right size.] Here. Hold this while I look at pants.