Yep, will be in Beijing on business and thought a night in Macau would be fun. But the cheapest flight I see is about $ 850 and not *A.
All my other trips within China were much cheaper and 1st class was only just a few $$ more.
Would I be better off waiting till I'm in Beijing to book the tickets there?
Domestic fares in China are calculated on a government imposed distance flown formula. There are some discounts available from the official fares depending on the destination. If you were flying to cities near each other it explains why your other tickets were much cheaper in comparison.
Macau and Hong Kong are both international destinations, so don't necessarily follow the same pricing formula as domestic fares.