can't squeeze another year out of non-O year extension based on retirement by crossing the border. You enter with the time left, which could be just a week even.
Need to do an annual extension at immigration.
The extra year by border crossing works for non-OA retirement.
I used to have to give bank statements for a lot more than 20.000 baht for a multiple entry TV in the days when I was young(er). 600K - 800K.. can't remember exact amount.
There was one time when my visa was under review, they even called me to send proof of no criminal record to get my visa approved.