Here is a switching regulator that costs less than $5. It does not require a heat sink or other components. Available at Digi-Key
http://www.digikey.com/product-deta...6882670-VQ2-g-VQ6-45013741995-VQ15-1t1-VQ16-c
http://www.murata-ps.com/data/power/oki-78sr.pdf