Wirelessly posted (BlackBerry8703e/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/104)
Your monthly spend is $250, and you're worried about maximizing cashback?
With that level of spend, it will take you years to get any substantial benefit.
If you can, just get yourself one of the Citi AA credit cards that are currently offering 30,000 bonus miles if you charge $750 within the first four months, and you can redeem for a free domestic coach roundtrip.