The cheapest flights to South Sudan recently found by momondo users are $142 with Uganda Airlines, $165 with RwandAir, and $193 with Ethiopian Air.
South Sudan has re-opened its borders; however, the South Sudanese government has suspended the issue of visas at its Embassies abroad, and all routine international commercial flights have been suspended since March 24. Humanitarian and evacuation flights may still enter the country with an approval from the High Level Task Force of South Sudan. Travelers wishing to enter South Sudan must have a certificate showing they are free from coronavirus, issued no more than 48 hours ahead of their journey, and endorsed by a reputable medical provider. They will also need prior permission to enter the country from the National Task Force. If you are planning to travel to South Sudan at this time, it is recommended that you stay up to date on current restrictions and follow proper safety measures while in public.