From memory the figures were something like $800,000 US per engine for the old engines, while the new engines cost something like $6 million each because of the new technology and exotic materials.
As you can imagine that existing users might think twice about saving a few tons of fuel per year at the cost of $24 million per plane... especially when the old engines still worked OK and got the job done.
Obviously the price will have gone down a bit as the new technology is mastered and with the Russian AF buying them the economies of scale should kick in and reduce the cost.
In many ways the Il-476 is an upgraded Il-76MF with new avionics and materials etc.
It is certainly not as good as the C-17 in terms of raw performance, but in terms of price it is very hard to beat and is the most successful medium cargo jet of its era. In comparison the C-141 was largely a military only aircraft that private operators hardly even looked at, while the C-17 is simply too expensive to buy to consider for commercial use.
Would love to see them decide to continue the Il-106 with new engines as the retirement of the An-22 will leave a real gap, between the Il-476 and the An-124.
Internationally I think it would be a useful competitor for the C-17 and in terms of price the only civilian commercial option with the C-17 simply pricing itself out of the market.