Oh and once again Ultrafast are still a LFC so you would still need an RSP (Retailer) to sell you the service to get an actual internet connection out of all this. Did I get that right Michael? (you seem like you know a heck load more about this than I do)

Yes. All they do is provide the network to connect the ISP to the customer.

By way of comparison -

Bitstream 2 - 100Mbps down / 50Mbps up
$55 - $58.75 depending on CIR

Bitstream 2 - 100Mbps both ways
$163.04 - $309.29

Prices per month and plus GST.

This is only for the segment of the link between Ultrafast and the customer. The ISP is up for other changes on top, like for example, the cost of the backhaul link between themselves and Ultrafast.

The considerable pricing difference is due to BS4 being an 'active' service. iE: All BS4 connections terminate directly into a switch, as opposed to BS2/BS3 connections with use GPON optical combiners before backhaul to the switch.
Please note that this is my best understanding. I am not 100% sure on this as the description in the price list calls it a GPON service which contradicts their claim elsewhere that it is active.

If it is an active service, the price is inline with other comparable 'business / carrier' grade services offered by Vector and Chorus (business fibre service, not UFB)