When would you want a 1024kb connection (with a cap)?
Never.
Every few months I download a new linux distro - 4 CDs (some are 6 CDs). 4CDs weigh in at 2.5GB. The complete download, usually takes less than 24 hours. 1024kb line will take 8 hours. Why would I spend an extra 300-400 rand per month, so I can save an average of 4 hours per MONTH?
Now, increase the cap to 60GB+ (or remove it completely), and I can use it for web radio, streaming video...