Although I agree that people get paid less here, I highly doubt that it costs an ISP in the US 8x more to transfer data than an ISP in Thailand.
I'm not really trying to argue that Thai internet is cheap, it's that internet elsewhere is exorbitantly expensive.
Porkbun! There are many to pick from but from my experience Porkbun includes everything you need out of the box at no additional cost. Namecheap has very good first year deals, but after that it almost doubles in price.
Which registrar you pick initially doesn't matter too much. I started with Namecheap then moved to Porkbun after a year with them (Completely free to move, but you'll have to buy an extra year if you move tho)
Don't use GoDaddy though. I was searching for a domain on that site and after a few minutes it was taken.