Today cobalt has about twice the price of nickel. However some 15-20 years ago cobalt was relative to nickel much higher in price, something like 5 to 10 times higher. The reason was political issues in the main African producing countries(if I remember right it was Zaire and one more).

There will always be cobalt in these kinds of nickel sulfide ores, just in varying amounts but typical fairly low with about 0.1 to 0.15 wt% as fairly typical values. I suspect that in all the sulfide samples with nickel they must also have found cobalt if they looked.

One difficulty with cobalt is that during the extraction it is hard to recover since it is very close to iron in terms of chemistry. One main purpose of any nickel extraction process is to separate the nickel from iron, and by doing that you also loose a lot of cobalt. While nickel recoveries may be 80 to 90% overall cobalt recoveries are easily less than 50%.