BTW, have you researched & understand how the recent changes in Thai income tax rules may or may not impact you living in TL? It's something I'd recommend you look into if you haven't already.
I don't understand your concern. Yes, it will cost him the first time but IMO if you don't know how to do it, it's best to hire someone who does. Also who is "they" in your comment? Also, you have choices with most agents. Either you can pay the agent extra to deposit 800K in your stead or once the account is open in your name, you wire transfer the 800K from your bank in your country.
I flew into TL on a visa exemption in 2017 and then I did exactly what I described to you above. I don't know where you will be living but I was living in Pattaya in 2017. That said & addressing BrandonThurkettle's concerns, I used Key Visa in South Pattaya & they were fantastic. I also see many people rave about TikTok visa & Motts Visa, although I've never used either of those companies. Recommend you search the group for "visa agents" & you are bound to find some positive testimonials.
IMHO, the easiest way to get your retirement visa (the first time) is fly in to TL, visa exempt. Once you're here pay an agent to open your Thai bank account & do your visa paperwork & legwork. Transfer in 800K and you'll be able to stay for 15 months (3 months for the first O visa & 12 months for the extension of stay.) During your 1st 15 months you can educate yourself about how to do your next extension of stay without paying an agent.
As many have already told you, a retirement visa is easier with regard to the paperwork but you must maintain twice the bank balance and you cannot work on the retirement visa. I've been married to my Thai wife 8 years next June and living in TL 7 years as of last month. We have a fantastic marriage. My wife is awesome. It's easily the best relationship I've ever had and I've had my share, including a divorce many years ago. I'm retired so I have no need for the work permit so I've decided to remain with the retirement visa. I considered switching to the marriage visa a while back but then I saw on the news where a Thai woman married to a Farang man died and he was on the marriage visa. He had to report her death to immigration immediately and they gave him 7 days to exit the country, since his wife was now dead and therefore he was no longer married. I think if my wife were to pass, the very last thing I would want to be dealing with would be immigration. I'd be busy planning a funeral and all the things involved with it and obviously mourning the death my wife. My wife is 12 years younger than I am, she's slim, exercises nearly every day and eats super healthy. I think it's unlikely she will die before me but hey, you never know, she rides a scooter and this is TL. Odds are if I switched to the marriage visa everything would work out fine but I guess I just like the autonomy of knowing that my ability to stay in country isn't all based on my marriage. That's my 2¢ on the matter. I wish you and your future bride all the best and I hope you are as happy as I am. Cheers ~ Bill
Wise ony sends into Thailand. There is a service called "Dee Money." I set up an account with them maybe 5 years ago and sent a token amount of money (฿500) just to test the service. It worked, I received the money in my US account. However, since that time I've seen other people post horror stories about their money being lost in the ether. Having read these stories, I would probably just use my bank's options if I need to send cash out of Thailand (e.g. Western Union, SWIFT or International Prompt Pay.)