I don't know specifically about InteliJ, but the product price is usually the lowest cost of a closed source solution. I work in a government owned company. We have strict procurement rules that we must obey to buy things. Beyond the procurement bureaucracy, now we have to manage how much licenses we have. The install of a new instance in a user machine must be tracked. A user can't by himself install the software, we must have specialized persons to do it. To setup test and/or disposable environments is a hell. If we reach the maximum of licenses, a high payed employee must spend time searching for who is not using the software to uninstall, and surely the person won't be available.

The price is probably the lowest cost of a closed source solution.