have you already have a Thai bank account? If not it might be challenging to get one now. Marriage Visa requires less money hold in bank 400k around 3 months but more paperwork than retirement visa. Retirement visa requires more money in bank 800k and can’t drop below 400k. You can opt for 65k monthly method later on. Less paperwork. So you choose which one is more suitable for yourself.
If you worry about your previous travel history. Just make sure you have hotel reservations for few nights, 20,000baht in cash or in other currencies cash and a ticket booked out of Thailand.
Have seen people got denied entry for not having a ticket out of Thailand recently.
This will increase your chances for getting in Thailand but not a guarantee.
you might pay a bit more at first. But you will save money in the long run. I have 24k btu Mitsubishi paid 35k baht 4 yrs ago estimated power bill at 12k baht per year. Another one is Haier 24k btu paid 25k baht 2 yrs ago estimated power bill at 20k baht per year.