There is no requirement for your funds (banked money of 400k thb) to be shown as an international transfer for your applications for a visa and a 1-year extension based on being married to a Thai. But you better check with your local office for their specific requirements.
Get the latest handout from your local office beforehand.
Here is the GENERAL requirements list for in-country Non-O based on being married to a Thai.
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/6.FOR-PROVIDING-SUPPORT-TO-OR-BEING-A-DEPENDANT-OF-A-THAI-CITIZEN-SPOUSE-VISA-NON-O.pdf
Attached is the GENERAL info on requirements for a 1-year extension based on being married to a Thai.