Amazon has the Case-It Laptop Backpack with Hide-Away Binder Holder (BKP-102 PURG, Purple Grey) for $12 with free shipping on $25+ or with Prime. Walmart has it for the same price with free in-store pickup. Fits 13" laptops.
Best Diaper Bag Deals, Nappy Backpacks on Sale
$12 retail: $40Report
eBay with Lenovo has the Lenovo IdeaPad Gaming 15.6" Backpack (GX40Z24050) on sale for $12 with free shipping.
Lenovo B210 15.6" Laptop Casual Backpack for $12 with free shipping
$12 retail: $30Report
Amazon has the Ben Sherman Noak Hill Vegan Leather Toiletry Travel Kit (Dome Travel Kit, Black) for $9.35 with free shipping on $25+ or with Prime. Overwhelmingly positive reviews.
$9.35 retail: $20Report