Houses one end, big drop-off and river at the other. RESAs are already the required length (bulk earthworks at one end to achieve this).
Real estate is limited in the valley and comes at a premium (at least it did pre-COVID).
It is and should be treated as an exclusive destination on the doorstep of multiple ski-fields in a gorgeous part of the world.
If you want to move payload, fly to Christchurch and hire a couple of buses
