Namesilo you can buy cheap domains with free whois privacy. Namesilo is (BY FAR) my favorite and #1 of all registrars available today.
I have tested paying for domains at Namesilo using Bitcoin. You need to top up your account with a $ amount, say $100 worth, and it’ll show a QR code, when you scan it with your wallet it’ll automatically show the address and price to pay. The process took 30 minutes, very smooth system.