There was a time where you had to pay for this, or when it was free, it was just free for the first year. I believe NameCheap was that way back when I first got into this hobby. These days, you shouldn't be paying a penny more for privacy protection. That service being included has become industry standard.
I used Namecheap to register the domains I have and the Domain Privacy Protection was offered free once I bought the domain name which I thought was awesome.
I believe most domain providers offer this for free now.
Thankfully it's free on Namecheap now. I can't remember how much it used to cost for the protection, but I don't think it was that expensive. So now I don't pay a cent to keep my information private.