@Nongnuch *******
>during this time he does NOT need any money in a Thai bank
That is correct. The visa is a multiple entry visa, that's good for a year, and on each entry a person is stamped for one year (from the date of entry). The immigration officers at the border *MAY* want to see health insurance, and may stamp a person up to the valid date of the health insurance. However, NO proof of finances are required.