There's an undercover tourist deal that ends 12/31.
Register your Amex card for a statement credit of $30.
Go through upromise for an extra $2.50 credit.
Buy your ticket via undercover tourist with your Amex. You'll get a $30 credit on your statement. Plus 1% cashback or whatever incentive you have on your Amex. Plus $2.50 through upromise.
That's the best deal out there right now.