The very latest type of batteries hold their charge much longer (than all the ones that I own) when not being used. They also cost three times as much, and need a different charger.

The reason that you see Makita in tradesmen's toolkits is that they honour their guarantee for professional usage. Black and Decker do not, at least not here.
The life of three pairs of batteries is about the life of the drill.

There are Makita copy batteries about, so buy from a reputable dealer.

Makita drills are also made in China, at least my two were. Can't tell about the batteries.