Originally Posted by
Nihon_Ni
Sounds like you might have an opportunity to SDC and add a few legs to arrive back home with 4+ segments for a day's effort at your $400 budget.
I would not count on this as a strategy, as there's no guarantee that you can add segments in this manner. UA has cut down quite a bit on their flexibility. Also, OP doesn't yet have Gold, so there would likely be a $75 charge per SDC.
Best just to book BUF-IAD-EWR-IAD-BUF for $274 if the one-way is $137.