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.
We had a similar experience with a closed source profiler. We paid for it, and the vendor repeatedly sent armies of sales engineers and even a core developer to help us use it.
Because of licensing enforcement mechanisms (we had a site license, FFS), we couldn’t figure out how to push it as part of the product to test or production clusters, so we just use perf, even though it has maybe 1% the functionality, is frequently wrong, and we desperately need the 99% missing functionality.
JetBrains does a pretty good job making this a bit less painful. They have a license server you install that dishes out floating licenses to IDEs. Floating licenses are released after 2-3 days, so if someone isn't using the product it doesn't consume a license.
The price is probably the lowest cost of a closed source solution.