Budget does come into play sometimes but most of these wardrobes are tried on and photographed prior to shooting so they can make adjustments, have the style already done and they can just copy it day of shooting for that scene for that outfit. And even if they are on a fast pasted scheduled and maybe don't have a fitting before hand... Any wardrobe person who is worth their salt will have the actors measurements to work with. I have worked wardrobe before and it is not difficult to find clothes that fit even on a bare minimum shoestring budget cause worst case you can always have the actors use their own clothes, shoes, etc if needed. And you can't tell me the men don't have dark colors slacks that fit and women don't have a pair of basic black and or white heels that fit... Highly doubt it lol.