grostore via eBay offers this 4-in-1 Car MP3 Player FM Transmitter for $2.70 with free shipping. (demonerrr via eBay charges pennies more; Yugster charges a buck more after coupon code "facebuck".) That's the lowest total price we could find by $2. It reads mp3 players, USB flash drives, and SD cards, and features an LCD display and remote control.