RepArchive has it's own shipping calculator that has grown into the most helpful tool in the whole scene.
It combines all the different agent shipping calculators on a single page, that's why it's called the ultimate shipping calculator. It also takes all fees, including hidden fees into account, as well as the exchange rate to give you the best price.
It pulls the data live from the agents, so it's just like opening them all in parallel, entering your information for each and comparing the results yourself.
You can refine the results with advanced filters and sorting options.
The shipping calculator is available here: https://reparchive.com/shipping-calculator