There are no more 30gig accounts (unless you mean 30gig of local) I dont think....
All i can say is that I use Imagine (an IS reseller , so i get 30gigs of local) they are one of the cheapest and their service thus far has been good....it does depend on how much and what type of bandwidth you want, and what you want to use it for...
It's has kind of turned into a crappy market out there...
No, for the most part 30Gb international is out (other than axxess who are still offering it) so far, for now, SAOL seem to be the cheapest go here -> http://www.mybroadband.co.za/vb/showthread.php?t=29736 to make your own comparisons it all depends on what you want, but if you want High-cap accounts, expect to pay...alot.
Best value for money SAIX Shaped accs is SAOLs 10GB for R350.
Best value for money SAIX Unshaped accs is Web Africa R125 per gb pre pay. (R500 for 4GB, unused BW carries over)
Im not really interested in IS packages so I don't know which would be best. Ill be going with a mixture of the above.