The remodeled Xbox 360 S came out at E3 in June of 2010, that also really boosted sales.
The new 250Gig Xbox 360 S was the same price as the old 120Gig Elite model, but has advantages including built in WiFi N, optical audio out, is smaller, quieter and cooler. Plus more USB connections and a built in Kinect port.
So they didn't lower price, but increase the value. The 4 gig Xbox 360 S version came out a few months later for $199.00 as the lower priced model.
PS Good thread, I had forgotten the lowest price X360, was more than the Wii for a time.







