Appliances Shipping Cost from Helsinki to Kigali

Finland -> USA, a regular postal service envelope (less than 30mm thick, 1.99kg) is 18.50 EUR (10-15 days). From Finland to USofA couriers are are starting around 25 EUR for 0.99 kg package (UPS, 6-9 days, delivery from a Finland UPS service point to recipient home). And not much more for heavier packets either.

Shipping to Africa from the USA varies wildly, from ~$20-$60 for small, light packages via USPS/budget couriers (weeks/months) to $100s for faster services (FedEx/UPS), and much cheaper per pound for large cargo via ocean freight ($0.50-$1.20/kg), depending heavily on destination (South Africa vs. Kenya), speed, size, weight, and chosen carrier like FedEx, UPS, USPS, DHL, or freight forwarders.

Very generally, your national postal service will be the cheapest way to ship internationally. The Universal Postal Union has been in place since 1874 reliably transferring documents and goods to over 190 nations. One interesting sidelight.