Can I order a refurbished product anywhere in the world?

First off, you might want to make sure that you are browsing your country's version of RefurbMe.
When you scroll down to the bottom of the page, you can switch countries directly.

Can I buy a refurbished product even if my country isn't listed?

Yes, you can use our partner MyUS to receive products from US merchants:

• You'll get a physical address in the US, that allows you to order products without paying American sales tax (as if you were based in the US).
• When a store asks you for the delivery address, you'll enter the MyUS address that they gave you.
• Once MyUS receives your package, you'll give them your home address, and choose a shipping method (UPS, FedEx) to receive your product.
• You can proceed to their site here

Regarding tax/import duty calculation, you can make an estimation on SimplyDuty.