@Brian *******
The answer to your question is, (ASSUMING EVERYTHING RETURNS THE SAME BEFORE COVID-19), yes!
A multiple entry Non-O visa will cost about 5K THB in local currency at the local Thai embassy or consulate. This visa is valid for one year. However, when you enter Thailand, you will be stamped in for 89 days. At the end of 89 days, you'll have to leave Thailand (generally to Laos, Cambodia, etc) and return. BECAUSE OF COVID-19, THESE VISAS ARE NOT BEING SOLD!
On a multiple entry Non-O visa, if you meet the financial qualifications, you can get a one year extension of stay based on retirement. This requires seasoning 800K THB in a Thai bank account for 2 months. A one year extension of stay based on retirement can be renewed forever.
IF the multiple entry Non-O visa is not being sold, you can get a single entry Non-O visa. This visa is good for 90 days, and on entry lets you stay for 89 days. If you meet the financial qualifications, you can get a one year extension of stay based on retirement. This requires seasoning 800K THB in a Thai bank account for 2 months. A one year extension of stay based on retirement can be renewed forever.
On an extension of stay based on retirement, if you want to leave Thailand and return, you will need to get a re-entry permit. This permit keeps your existing extension of stay alive and can be purchased at any immigration office.
If you're planning on entering next year, I highly recommend waiting until we see what happens after COVID-19. Things are changing weekly here now.