It really depends. I’m on the go so I can’t dig deep, but news reports keep saying Russians used cruise missiles.
A Russian Kh-101 costs about $18 million USD. A Kalibr is somewhere between $1 and $6.5 million USD (sources are a bit muddy and I think the high end is more like the export price).
There is a wide variety of air defense systems from many countries in Ukraine, but for example a single Patriot missile, a long range defense for shooting down cruise missiles costs about $4 million USD for the US. The cost of the launcher is about $1 billion (with a b) for the US. In this case you can see the missile is, relatively speaking, cheap compared to the whole system.
Keep in mind there is a ton of variation. Russia allegedly also launched drones, and a drone is a pretty wide category of size and price.