This must be Amazon.com's best kept secret. Amazon has an unadvertised 30-day price guarantee policy. Which means if the price (before any coupon or rebate) drops on any item (sold by Amazon.com, not from a third party seller) within 30 days of your purchase, you can request a refund on the difference.
To request a refund, just call 1-800-201-7575, extension 7 or simply
Click Here to send Amazon an email. Amazon will credit you back the difference normally within 1 business day.