Post or prepaid
 

I have been on prepaid with three different mobile phone networks now in the two months that I have lived here. My usage has been low but the cost is relatively high. I don't have a set of numbers that I call regularly which is what a lot of plans offer to let you call for cheap. I also don't make length calls and average 1 to 2 minutes per. I am currently on Telstra with the thinking that I would use data for email but as I have used the credit up so quickly with just calls and the odd sms I have held back on buying the data add-ons.
Should I go postpaid if I think the call rates are high and if I do which networks give me gprs preferably at edge speeds albeit for an extra charge? A small bundle of sms' would be good too.