Paid subscription feature is not very basic now.

You can limit

1. number of uploaded video
2. file size (this is rounded figure now, that is 2.1 MB will become 2 MB, 2.9 MB will be considered as 3 MB)
3. Bandwidth limit, it just calculate size of the video, it will not measure actual video data served to client (this is not possible with FLV http streaming).

So if you enable subscription, have flat rate subscription, not much depend on bandwidth or disk usage. Most subscription site, it will work.

We will be adding more features, but it will take time.