Xbox 360 Wireless Controller for $19.99.  Add it to the cart and change the quantity to 2 to get free shipping so you end up with two Xbox 360 wireless controllers for $39.98 shipped.  Here is a screenshot for your reference.  It includes a wireless receiver and features wireless 2.4 GHz with a up to 30-foot range.  As a comparison, getting two of the Xbox 360 wireless controllers at Best Buy would add up to over $75.