50mbps Unlimited NBN plans are becoming more affordable since NBN co dropped the wholesale prices in Decmeber 2017.
Barefoot NBN & Mate are both offering unlimited NBN @ 50mbps for $59 per month. Hello Broadband is offering their unlimited 50mbps plan at $59.95
If customer satisfaction is your thing, Tangerine Telecom have 4.1 star reviews on Product Review, and their 50mbps unlimited plan is priced at $69.90
If unlimited data is not necessary, you can get 100gig with Exeltel for $49.99
*All prices were taken from Whistle Out on 22/02/18 and can change at any time.