I am a trader living in Thailand. Been trading for 11 years. I have the Thai Elite Visa. Thai Elite Visa is the best, you don't have to worry about anything. It's all taken care of for you through their concierge service.
Everyone is different. For me personally, I spend around 350,000 baht per month. There is a difference between need and want though. I spend this much because of the things I WANT to do.