The business is in Auckland, not far from the CBD. Currently we are with Callplus on naked ADSL2+ at about 24Mbps. We get unlimited data for about $80 a month. It's been cheap and reliable, but our users are greedy. They use about 1TB per month. So the internet is often slow. I guesstimate there may be around 25 users at peak times.
The only provider I have found who offers unlimited VDSL is HD.net for $249 per month naked. That's triple the price for hopefully about twice the download speed. But it still may be worth it. Are there any other ISPs who offer unlimited business VDSL? Voyager offers 1TB VDSL naked for $169 but excess is $1.50 per GB, so that is no good. The usage will no doubt jump with VDSL.