ghoti: It's around $1/W for a big wind tower, but the cranes (a big crane to put up the tower, and a small crane to put up the big crane) cost a cool million to rent for the season and ship up and down.
So except for the larger communities (3k people or more), it's better to put in small towers. 100 kW can be put up with much cheaper equipment.
Most of the generators in the North are the originals that were put in back in the 1960s, 70s, and 80s when the government decided electrification should occur. They're not only at end of life, but the population has increased and demand per capita increased.
Sebastian: indeed! In Nunavut, residential customers see heavy subsidies, about 60-70% off the total cost. Commercial and government pay their fair share. In Quebec, rates are set based on cheap hydro in the southern half of the province: 5.75c/kWh up to 8.5c/kWh depending on usage... and by law, remote communities get the same price! So that's about a 80-90% subsidy.
The total cost includes capital expenses for diesel generators, but renewables on their own don't help reduce the size of generators you need. The peak is early-evening in winter. Solar doesn't reduce the peak at all (every early evening in winter, the sun is set), and wind doesn't either (there's enough early evenings in winter to pretty much guarantee one of them will have calm winds).
Batteries, however, do reduce the peak demand for generation capacity -- store it up all day, then drain the batteries during the peak -- and to use renewables on a small grid you pretty much need batteries anyway (to provide the "inertia" that smooths out supply and demand mismatches). That's a nice synergy.
One of the major problems here is access to capital. As I wrote on Ars on a recent thread, a mere billion dollars would modernize the entire Northern set of microgrids in Canada. That money is getting spent anyway on various things here, but there seems to be a problem matching up the supply of money and the demand for it. My partner's group is working hard to solve a tricky problem: how to blow a couple million by the end of FY2017 on initiatives that are within their mandate. Meanwhile, the power company is holding off on renewables for want of access to capital.