MYW prices are sure to increase soon. I doubt they will increase APs again by January, especially with the huge increase the Platinum and Platinum Plus took in October.
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.