Not a question at all, just a link to a Domain Registrar called Porkbun, at the moment they are having a sale, so most TLD extensions are cheaper than other providers, of course like many, its mainly first year discounts.
However, when I visited Porkbun from your link, I noticed that .design TLD costs $5.98 for the first year, then it renews at its renew price (aka $35.47). So that is a fake news.
For “transfer the domain name” did you mean “add the domain to your free hosting here on InfinityFree”? To add the Porkbun-registered domain name to your account you may need to wait 24 hours, not 72 hours, to the nameservers changes to propagate.
For me it’s useful, but I prefer going elsewhere to register my domains. Google Domains has prices that start from €12 to register the domains, and .website TLD costs €19 per year without sales on them.
being “cheaper than other providers” is not hard given the rip-off which many registrars perform.
but try find one that sells .xyz for less than 1€ per first year (only) like INWX !
you may wanna watch out for cheap .€U domains though. since the BREXIT debacle they are so desparate about their failed scheme, that they stop at nothing to get people to buy into the .EU mess at lowered fees. Won’t stop the €U collapse in due time of course.
cloudflare claims that they charge the price of the TLD owners only without any markup. seems you cannot get below € 5 per year in the cheap cases such as .de (1st year promo stuff excluded)