The visa and the re-entry permit are two different things with two different prices. All I learned about visas I learned from Tod Daniels. He is the final word on all thing visas. Or at least he is one of a few experts moderating this group.
After my first year I purchased a multiple re-entry permit but it expired on the same date as my last stamp in my passport. I only got 9 months use. Now with my 1 year extension I will get the full year of my new multiple re-entry permit.
I arrived in February 2017. I made three trips to the US and a final trip to Cambodia in Nov 2017. I was stamped in until November 2018. I recently got my first 1 year extension.
I just got my year extension in Bangkok. I could meet both the income requirement and the bank requirement. If someone else can do the same then they could try meeting the income requirement with bank statements. If that doesn’t work then they have the bank deposit as a backup.
I believe it is only 2 months the first time you get an extension of stay and 3 months for each additional extension. Best to play it safe. You have time to get your money here. I got my first yearlong extension 3 weeks ago. I did based on the money in my Thai bank account.
When I got my year extension two weeks ago the officer stapled to my passport. Now when I fill out a new arrival card I immediately take a picture of it and store in my immigration album in iPhotos.