As far as I know, Cloudfare is the only registrar that offers you wholesale price, as in the price asked by the tld owners. So, you a registrar can’t go lower, because that’s what they pay for it.
But, a lot of registrars will give you first year at a heavy discount (so, at a loss), just so they can ramp up the price to wholesale + a lot extra. I got my domain for like 5$, and they then asked for 40$ for renewal, while wholesale is around 25$.
So, I just transfered to Cloudfare for the renewal. Tbh I don’t remember if it was the first or second year, and what are the transfer rules, but I think it should be possible to just buy a first year at heavy discount with i.e Namecheap or something, and immediately transfer to Cloudfare for the first renewal at wholesale price.
I recommend transfering to Cloudfare, since they have guaranteed wholesale price (no added fees, and only what the tld owner and ICANN asks), so they should be cheapest (since anything less is selling at a loss for the registrar, at least ifI understand right).
Namecheap has started overcharging me like 20+$ on a renewal compared to CF. So, transfering after a first year (which is where registrars like Namecheap take a loss and give you a discount) is probably the cheapest way how to go about it.