@Bill ********
retirement visa has different requirements. For a retirement visa extension you need bt800,000 in your account for at least two months, then for three more months after you get your stamp, then after those three months you can use some of the money, but the balance can never drop below bt400,000 for the rest of the year, and brought back up to the bt800,000 at least two months before the next year's extension.
A marriage visa extension requires bt400,000 in your account for at least two months before you apply, and here is where the difference is, as soon as you get your one year extension stamp you can do anything you want with all the money. It only has to be in your account at least two months before your next year's extension.