If you are visiting NYC, you've got to go to the BV boutique (699 Fifth Ave.)!!! Saks (611 Fifth Ave.), Bergdorf Goodman (754 Fifth Ave.), and Barneys (660 Madison Ave.) also carry BV and they are all in walking distance.
I haven't been back to Century 21 for ages and don't know if they carry BV. I know that they have good bargen items but it was so crowded and hectic and things were all over the place when I went there. It sure is a popular spot though.