Old Navy has really had some great J Crew dupes lately - and at a price point that's more than 1/3 of the cost. I picked the following striped sweatshirt up this weekend during a 50% off one item promo and couldn't wait to wear it today. I paired it with chambray and a black sweater skirt.
Striped sweatshirt: Old Navy (exact)
Chambray shirt: Nordstrom (similar)
Skirt: Loft (similar)