Dell has $15% off
15% off Coupon code: 6FWJ247J1P44CK
plus sign up for a Dell Preferred Account and get another 3% off
So absolute cheapest an Arcade will cost you $165; it's the Jasper with $512MB internal memory so that will keep you going until you can pick up a used 20GB hard drive (typically $30 on ebay, but if you're patient you can get one for $20). $5 for an HDMI cable.
Or spend a little more and get a Pro for $206 that comes with a $60 GB hard drive; not sure if it still comes with a component cable but from the specs they are all Jaspers.
*** I think all states pay tax from Dell, so keep this in mind if comparing to other online vendors
edit: also Target has a deal with a free controller, so if you need a 2nd controller that might be competitve