I am traveling IAD to Capetown late next May and unfortunately don't have nearly enough miles left. Of course the Polaris/Business class tickets are PRICEY!

I've watched the round trip price go from around $4,000 a month ago, up to $6,300, down to $5,300, up to $5,600, and back down to $5,300 today.

When should I pull the trigger? It's a new itinerary for United so there's no price history.
Only 4 of the 48 available seats have been booked on the outbound, only 3 have been booked on the return. Does that mean I should wait? What's the strategy?

Thank you!!!