Xbox 360 250GB for 263.99 @ Drugstore.com (potentially less with cashback)
1)
Activate the 20% off sale:
Link: http://e.drugstore.com/a/hBNbREIAbeh5-B8ZYJBNshgmV.Abeh5-Xu/win
2)
Then add the Xbox via the product page:
Link: http://www.drugstore.com/microsoft-xbox-360-system-250gb/qxp311
Add to cart.
3)
If possible, don't forget to take advantage of a cashback sites (i.e. 10%
for Discover Card).
Additionally, you'll get 5% of your purchase back in drugstore credit to use
for future purchases.
Final costs: $329 - ($66) = $263.99 + ($13.20 future credit)