If you want to easily update prices across registrars, you need to have everything organized in excel for the CSV imports.
I found it easier to make my own private website and import all domains into woocommerce. It's easier to navigate through all my domains, keep them updated and categorize them by different keywords on a website than in excel. Visualization is much better, sorting and searching much faster inside the store ui with comprehensive search functions.
You then can export the woocommerce CSV ready to be uploaded on the different registrars, very straightforward process. All for free on AWS with free tiers.