Im not planning on buying a 360 anytime soon, but on another site someone was kind enough to share the BestBuy ad that will post this sunday (10/28)
Below is a link to the page that shows a $279.99 price for 360 arcade edition.
This seems like a good deal to me.
click on "Best Buy 10-28 pp 1, 2, 3.pdf (718.8 KB, 894 views)"
Then scroll down.