I used the GoDaddy valuation tool and it tags in black/white "Premium" to names with a relatively high valuation. The text is omitted if not considered Premium. I was able to list - pending review - a couple premium tagged domain names on Afternic which is owned by GoDaddy and should feed the same auctions listings you see on GD (and more last I knew). I was also able to list a domain name NOT tagged as premium on GoDaddy Auctions. So that tagging seems to identify which will have problems being listed.
https://www.godaddy.com/domain-value-appraisal/appraisal/
GoDaddy .CO standard and discounted RENEWAL pricing hasn't changed as far as I can see.
.co $34.99 / $24.99 - 28% Off
https://www.godaddy.com/domains/discount-domains.aspx
And just a recap for those whos heads are exploding while reading this 500+ page forum post...
How much does it cost to renew my .CO premium domain name?
Last Updated: Aug 13, 2018
Whatever PREMIUM PRICE you may have initially paid to register your .CO premium domain name, your annual renewal fee will be the “standard” renewal fee charged for all .CO domain names.
http://support.go.co/customer/es/po...-to-renew-my-co-premium-domain-name-?b_id=497
Let's see what happens. At the moment it seems that .CO and the participating registrars are setting a floor price for .CO domain names (not to be confused with renewal prices which haven't changed). That's new data for the market. Not sure if .CO, GD, and Estibot valuations agree though. Anyone care to drop some samples of all 3 valuations into the thread?