If you are LEGALLY married and even if your wife has never touched the US soil, still you CAN file Married filing joint thru ITIN.
Married filing joint saves handsome amount of money if you have made 50K+, It's up to you whatever way you wanna go.
If I were you, I would investigate/research more, Google, call IRS.... It's not only about getting more money, it's find out exploring legal way/right way. Good Luck