Feanor, from the MoD video, it's not clear which part of the Caspian the missiles were launched from. Shoigu confirmed the ships involved: Dagestan, Grad Sviyazhsk, Uglich and Veliki Ustiug.Deployment? Which part of the Caspian were these missiles fired from? When you consider their ~2600km range.
But you're right on the price tag. They're quite expensive. If they continue using cruise missile strikes, the bill will go up fast. Then again this might have been a show force as much as an attempt to strike major military targets. The Syrians are launching a major offensive right now. I'll make a big update post later.
I wonder if strategic bombers will be used soon, especially if Iraq requests strikes. I think there is an element of showmanship but at the same time, cruise missiles have their utility that goes beyond shock and awe.
It's a rather paradoxical situation now. Just as the Russian military is on the verge of a relatively costly campaign, its budget for next year is likely to be sequestered by over a hundred billion rubles according to the Finance Ministry.