MegaMacs offers the Timbuk2 Pike Command Laptop Messenger Bag in Black for $83.49. Coupon code "CaseDeal" drops it to $73.49. (You'll see this price at final checkout.) With free shipping, that's the lowest price we could find by $31. It's TSA-compliant and features an internal organizer, adjustable shoulder strap, and holds laptops up to 15".
June brings some big deals and sales, but you're better off postponing certain purchases.