As another said get a ticket. You can come for 60 days no visa and extend on a 1 year retirement visa. There are longer options, but I advise doing one year first. I am on my third and it's easy enough to get, but they have a new 5 year which I will try next. Also don't ever send anyone money in Thailand or for that matters any country.
I don't personally care which path you use and so do what you like and feel good about. Others have asked about the agency that I used and so I gave information to help them. Since you have been here many times, you know there are various paths to living in Thailand. Enjoy!
not sure where you get your numbers, but they are not representative of what I paid which was around 25% of your upper number. This was from an agency that I have used before, so I continue to use them even they weren't even the cheapest that I had the option of using.
because he is talking about using an agency in the USA. I am not criticizing your advice, which I agree will be less expensive, but will cost less than an agency in the US. Also, not sure where you get your cost from, but my experience was much less expensive and gets cheaper every year, but mostly it is simple and as I said takes very little time.
It's much easier and cost less to simple fly here as a tourist, which doesn't require a visa for USA, and
then for a small fee you can find many visa agency's that will, in a few hours, get you from their office, where they will prepare all documents, to the bank and to immigrations. Based on your plans, you need to have them add a multi entry stamp, so you can leave and come back on the same visa. It's going to be much less trouble and time to just do it here. I go through this process every year and just finished my third time which took only one hour this time from start to finish and most of that was in transit.