My wife is Thai and she travels on her American passport. We visited Thailand 🇹🇭 from the USA 🇺🇸 many times over the last 15 years and never had a problem.
Plenty if you live within your means. With that amount you should even be able save some each month.
My wife and I are currently in Thailand 🇹🇭 and have been here for 4 months. We budgeted 3,000$ per month and it has been more than enough including our shopping and nice dinners out once in a while. Best of luck to you!!!
I would recommend the retirement visa as you only have to report quarterly after your visa is approved.
I am here on a non o multi entry one year visa; however, we had to leave the country and return as each entry you get only 90 days even though the visa is good for a year.