Premium domains are perceived to have higher value than average domains and therefore their renewal often costs more. Many factors make a domain premium — keywords, length, brand value, age, etc. Domains of one, two or three characters are usually considered premium. The higher price applies to the initial registration fee, but it can also apply to transfer and renewal.
It is difficult to determine in advance if the domain’s renewal price is above the standard one. Some domains renew at the regular price for the given extension, while others differ. For example, domain registrar Dynadot doesn’t have premium prices for domain transfer and renewal of the .tv extension so they cost the same as for regular .tv domains.
When it is hard to tell how much renewal costs, you can find out by starting a domain transfer to check how much the registrar will charge you. Of course, prices are subject to change, so it’s good to keep that in mind, too.