IIRC, it’s the ballistic missiles that are the big problem, and only the (US-supplied) Patriot missiles can hit them with any degree of reliability.
France has a counter-ballistic missile called Aster, but it doesn’t seem like Ukraine has many of them yet
This video is probably worth many thousands of dollars.
The IRIS-T missile is about half a million euros. Estimates for the Kh-101 seem to vary widely from about a million euros to over ten million, and I have no idea how to tell who is more likely to have guessed right. Either way, probably a good trade even before you consider the target that didn’t get hit as a result
250k to 600k, depending on estimation, number bought at a time, and also model. The 250k is apparently the cost without taking development expenses into account. Overall, since 2005, probably less than 10k missiles were built so that’s also the number without significant economies of scale.
The different models are basically the same but with different amounts of fuel (and thus also longer/shorter), prices shouldn’t differ drastically. Basically they started out building a missile that could hit a target when it was launched upside-down, spinning, pointing in the wrong direction, from a jet and then said “well slap a bit more fuel on that, it definitely won’t mind launching upright from the ground”.