Oops, sorry, I seem to have messed up with the prices – there’s a 2k difference between Novokuznetsk and Novosibirsk (9 --> 7). I guess I was looking for tickets for two people and didn’t notice it somehow. So, the question of which city to fly to remains open – maybe it doesn’t make sense to bother with Novosibirsk for 2k and spend an extra 3-4 hours traveling by bus.
P.S. Dirty, if it’s not too much trouble, could you estimate the prices and travel time for transfers from Novosibirsk airport and from Novokuznetsk? Then we can compare. I think it makes sense to plan for approximately 10 people.