Boost Mobile is running a Halloween coupon promotion that takes an additional 10% off the price of all phones and accessories at boostmobile.com.
To get the 10% discount, enter the code HALLOWEEN in the Promo Code field on the Boost site's Shopping Cart page. The code is good now through Halloween, Oct 31.
The best deals are on phone that are already on sale. For example:
Boost's top of the line Samsung Galaxy SIII LTE Android phone is on sale for $349.99 (reg $399.99. With the code it's $314.99.