It really depends on what kind of rocket you’re talking about. An unguided rocket propelled grenade mass produced with 1960s technology is a few hundred bucks. Stepping up to a simple TOW guided missile using 1970s technology quickly ramps that price up to $5-10k per round with a max range of 3-5km.

Once you add in modern electronics and guidance and reliability that cost quickly skyrockets, going up an order of magnitude at each step of complexity (advanced guided like the Javelin, cruise, ballistic, etc).