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.