Do you know that all major domain registrars (NameCheap.com, GoDaddy.com e.o.) every month release new coupon codes. If you want to register a new domain name, you can always get a discount from the full price of the domain registration fee if you enter a coupon code at the checkout.
So before registering it is a great idea to look around for a coupon code (search on Google for “coupon code namecheap” or “discount code godaddy” etc.). For example, if you register your domain name in April 2019 using NameCheap.com, instead of paying regular price, you can get a discount using discount code DOMSEEDS. This coupon code is just for new domain registration, it will not work with domain renewals. COM domain will cost you only $8.88 + $0.18 ICANN Fee this way.
Sometimes NameCheap.com issues a promo code for domain name renewals, but it is very rare. By the way, if you have more than 50 domain names with them, you can request a personal coupon code for all of your domain renewals.