@Ron *****
&
@Jim ******
the "combo-method" is part banked money (which has to follow the seasoning rules, funds in the bank 2 months before you apply, funds stay in the bank for 3 months after the extension is granted, then the funds can't go below 50% of the balance for the rest of the year and part monthly income (which has to be done via international transfer into a thai bank account in your name only for the previous 12 months before you apply for your extension).
Some offices WON'T accept it even though it is a valid way to meet the proof of funds, SO before you decide to jump on this bandwagon to meet the financial requirements check with your particular immigration office to see IF they accept that method