Comparison site WhistleOut has carried out an analysis of the four ISPs that have made public their NBN consumer plans on the National Broadband Network: Internode, iiNet, Exetel and iPrimus.

The results show prices for the NBN's entry-level plans would be cheaper on a per gigabyte usage basis, than the actual ADSL 2+ and phone line rental plans.

WhistleOut director, Cameron Craig, said consumers would be saving between 23 and 43 percent on their fees for an entry-level speed plan. 'On the NBN's entry level speeds (12Mbps and 25Mbps) we found consumers will actually be paying less than today's ADSL2+ and line rental plans for the equivalent usage."

According to figures released by WhistleOut, consumers on a sub 50GB plan , with a speed of 12Mbps, will be paying an average of $1.53 per GB compared to the actual average price of $2.01 on an equivalent ADSL plan. For consumers on plans ranging between 200GB and 1000GB, with the same minimum speed of 12Mbps, there will be higher savings, with the average price per GB being $0.13 against the present price of $0.23.

However Craig said that as speed would increase with the rollout of the NBN, so would the prices for the relevant consumer plans."The highest increase [will be] a combined hike of 66 percent across the four providers over today's prices when you look at top NBN speeds of 100Mbps and mid-tier data usage,"he said.

According to WhistleOut, 10 percent of Australians are connected to HFC networks and able to access the Internet at speeds in excess of 24Mbps, and 55 percent are on DSL services with advertised speeds of less than 8Mbps.

Commenting on these figures Craig added that Australian consumers, on speed plans from dial up to ADSL 2+, often were not sure of the speed they would actually get. 'The NBN's biggest benefit will be the democratisation of high speed access,' he said.

Telstra and Optus are yet to release their pricing plans.