@Scott *******
there is a HUGE difference from when your VISA or EXTENSION OF STAY expires and when you want to go APPLY for the new year extension.
Most immigration ofices allow people to apply for a new extension when you have 30 days or less left on your current stamp (Bangkok, Chiang Mai, Phuket, Buriram and a few others allow it when you have 45 days or less left on your stamp).
SO showing up a MONTH before your visa expires to apply for a new extension you'd ahve to have the money fully seasoned on that date NOT the date your stamp runs out.
Very few people actually wait it out until their stamps almost running out to apply because you don't lose any days applying early (the add the next year to your expiration date) AND if you're missing any documents you have time to sort it out.