Originally Posted by
jsloan
Prior to the DOT guidance about refunds, I'd have expected any schedule change that reduces the transit time between IAD to DCA to be enough to allow for a change either to the non-stop or a one-stop. Now, I'm less confident, but for $6K, I'd spend a day in DC.
OP is starting from EWR, so you're suggesting EWR-DCA-EWR-IAD-JNB, with DCA-EWR-IAD nested inside the EWR-DCA//IAD-JNB fare. That's... a day.

I initially thought that as well but had to re-read the original post.
OP is not stating in EWR. They are starting somewhere else (e.g. TPA) that has a connection in IAD/DCA, requires a transfer between IAD/DCA to get to EWR then onto EWR-JNB non-stop. The TPA-EWR-JNB itinerary is $6K more.
I agree with others that for $6K it's worth a day in DC. But OP hasn't said the time of year they're flying.
-RM