ThinkGeek offers this CB Radio iPhone Handset for $3.99. Coupon code "FIFTHOFF" cuts it to $3.19. With $6.04 shipping, that's the lowest total price we could find by $4. This handset plugs into your iPhone and features an answer and hang-up button, volume control and power on/off dial, mute button, and belt clip. Deal ends April 13.
Before you send in your tax return, double-check that you haven't made one of these mistakes that can trigger IRS scrutiny.