I like the model used in Australia, 0MB, 500MB, 1,000MB, 2,000MB, 3,000MB, 10,000MB and uncapped under 3 or 12 month contracts, excluding modem cost. Any usage over cap is charged at x cents per MB. They also have the ability to move up and down caps at a charge.
South African rollout is likely to be bundled and priced differently though.
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