Here at Lifehacker HQ, we're not usually concerned with the intricacies of NBN construction contracts. However, we figure this one is worth noting since the Northern Territory is one of two states and territories which don't yet have even pilot NBN services in place.
Syntheo (which also got the WA contract) will roll out NBN infrastructure in SA and the NT for an initial two-year period, with an option for a further two-year extension. The first building work will happen in Darwin and the Adelaide suburbs of Modbury and Prospect, though services likely won't go live until 12 months after that.
Construction work began in WA, the other currently NBN-free state, in October this year; the ACT is being counted as part of NSW. Currently announced pricing for NBN services is listed in our Planhacker spreadsheet, though it's worth pointing out that there are still lots of major providers, most notably Telstra, that haven't announced prices yet.