First year, you need to deposit 400,000THB as soon as you get here. Then you only need to transfer 40,000 THB per month from as soon as you get here. This is small money. I really don't know any Farang that can survive on 40k. You need to apply for a Non-O Visa before coming to Thailand. A very easy process which you can do with the help of your wife.
I bring over a minimum of 100,000k per month and live very well on that. I'm 63 and my health insurance 132USD per month for 400,000USD coverage.
Here's the Official Royal Thai Embassy Portal where you can apply in most civilized countries.
****************************