METV is your best bet, just done mine, landed in Thailand 10 days ago. Relatively straightforward process. Gives you 90 day continual stay (60 +30). If you leave and re enter on final day of visa you get additional 90 days,so 9 months in total.
I rent a studio in a great building no contract just month to month for $300. I rent a small scooter $80 a month. Unlimited data and calls mobile package around $15 a month, wi fi is free in my building. Eating out Thai food/ street food around $ 12 a day but depends on what you prefer if you want western food or enjoy nice restaurants then its going to be more. I think you're way over on most of your budget but I live pretty cheaply. Main costs are booze and women 😆. I've lived here 4 years so any questions just ask.
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