Newegg.com has
Lowepro Fastpack 250 Backpack for $49.99 with Free 2-Day Shipping.
Amazon has it for $89.99.
1 digital SLR with a mid-range zoom lens attached plus 2-3 additional lenses or flash units (up to a 70-300 f/4.5, 15.4" widescreen notebook, memory cards, batteries and cables)