Yes, the Bible Society prices do seem very steep. There are numerous reasons for that. Prior to 1994, the Bible Society in South Africa was tax exempt. Cape Town was one of the largest Bible printing cities in the world. The volume was high and therefore the unit costs were low.
Also, the South African Defence Force (SADF) was the Bible Society’s biggest supporter. Most of the tithes of SADF national servicemen went directly to the Bible Society. In addition, many of the units engaged in extra fund raising initiatives to fund Bible translations into indigenous languages and even into Braille. The Dutch Reformed Church also donated millions of Rands every year to the Bible Society. Therefore the Bible Society of South Africa was, in the past, able to massively subsidise Bibles, particularly in indigenous languages.