As the title states, purchase the Microsoft Lifecam VX800 from JB Hi-Fi for $5, claim 30% cash back on RRP which is normally $24.95 and get cashback of $7.49 = $2.49 profit. Use your $2.50 for something off the small change menu at MacDonalds. Will depend on stock in-store. Not available Online
For anyone even interested in the webcam the specs are here:
http://www.microsoft.com/hardware/en-ph/p/lifecam-vx-800
If your to lazy to look at the spec page all you need to know is that it's VGA.
For me I'd probably use it to monitor my cat throughout the day.
Price Error Again?