I've been out of the domain game for years now. Just going through Godaddy closeouts and find something decent for $7. Add to cart, they want to add .com renewal for $19.99/yr. Huh? First who pays $19.99 to renew a .com - not me. I thought buying an expired domain included the renewal?
Whatever the case - is there any way to get around this ridiculous rip off and actually buy closeout without having to add $20 to every purchase? Quite defeats the purpose of "cheap" otherwise.
You can try using a coupon code of 20, 30, 35% discount -what you just did- (and maybe if you buy enough a couponcode that gives you discount if you buy for more then 50 or 75 $). But other codes don't work any more with renewals.(and technically in the Aftermarket you pay additional to your bid, a renewal).
Look here in this thread =>
https://www.namepros.com/threads/godaddy-discount-codes.577802/page-898#post-5759064
The reason is money of course. In the thread above you'll find that in the last year big change has happened : For new .coms or transfers, you don't get 0,99 or 2,99 codes any more to work. If you once used such a code with your account, you can't use it in the future any more.
About your problem => There's
another solution => You can avoid this problem
by becoming member of the "Godaddy Discount Domain Club". (= between 110 and 140 USD/year, depending if you live in the US or not, -because in Europe VAT has to be payed upon the membership-).
One consolation =>BUT You can use a 30% , 40% or 20% code for paying your membership of the club, so that the membership doesn't cost you as much, when you buy it for 1 year (or more). (You should get your membership then for 75-115 USD or so depending where you live.
Membership gives guaranteed some 40% discount on a lot (but not all) renewals ((and sometimes if you are member you can use an additional %-code that gives not that % but an additional 10% off.)). =>
https://www.godaddy.com/domains/discount-domains.aspx THIS LINK WILL BRING YOU TO THE PLACE WHERE YOU CAN BECOME MEMBER. And if you click on "Prices", you will see the pricing (guaranteed, unless of course some changements in the pricing from a registry occurs).
So for new domains AND ALSO for renewals you get discounts with this Discount Domain Club membership. 
