STARTING TODAY
• Castor & Pollux marked down clothes by Acne, Built by Wendy, and 3.1 phillip lim by up to 70 percent off. Through 9/12. 238 W. 10th St., nr. Christopher St. (212-645-6572); Mon.–Sat. (noon–7); Sun. (1–6).

• Mick Margo's online sale section features big discounts on their stock of cardigans, skirts, dresses, and more. An Alexander Wang T-shirt dress was $276 and now is $138.

• Gilt Groupe slashed prices on Charlotte Ronson’s sweet, feminine frocks. If you're not a member, click here for your invite.

STARTING TOMORROW
• The end-of-summer sample sale at Project No. 8 features extra discounts on men’s and women’s apparel from Martin Margiela, Sunshine & Shadow, and more. Through 9/6. 215 Centre St., nr. Grand St., second fl.; (212-925-5599); Thurs. (5–9); Fri.–Sat. (noon–7).