Aoraki Court Motel is a good mid-range accommodation option in Mount Cook Village.
Note: the term "mid-range" is wildly inaccurate by my usual standards, as rooms start from $350 per night. But, this is considered "mid-range" in Aoraki as it's one of the most expensive corners of New Zealand.
Each room is self-contained with a kitchenette, underfloor heating, and a private bathroom.
The location is unbeatable and just a three-minute walk from the centre of Mount Cook Village and some of the most popular hikes like the Hooker Valley Track and Sealy Tarns. The motel doesn’t have an on-site restaurant, but you’re right next to the Hermitage Hotel, which has an on-site restaurant.
As I said, rooms start at $350 NZD per night. Since Mount Cook's accommodation is in high demand, I recommend booking well in advance!