Thai policy can always change.If and when Thai economy recover then it might go back to 30 days for most Asian countries. Thai only give long term (retired) resident but NOT permanent resident. A lot of difference because long term can expired,(even if it is 15 years) and policy again can be change so its not permanent. Example now it need 800,000 TB for long term visa.As time pass this amount would definitely increased depending on how Thailand prosper and it could grow to be 5 million Thai Baht. Whereas permanent resident is practically permanent and no change to the terms.