We were paying over $1M/yr for it inclusive of support. One real production instance (with Veritas Cluster), one reporting instance, 3 dev/QA instances. This was circa 2012, when the company had roughly $300M/yr in revenue.

I heard that a year or two after I left the company got an Oracle Audit and ended up paying a huge penalty.

Not one time and based on different things. Don't look that way

Some older context is they price per CPU core and I remember something like $10k/CPU core per year. This is from years ago and there were "enterprise" agreements in place and many millions of dollars being spent. I can't imagine they lowered prices other than maybe cloud offerings.

The support contract costs more than the "license" if my memory serves me, but its very expensive. If you're doing anything remotely complicated, using their advanced tools beyond a basic RDBMS (replication, clustering, etc.) then you need that support contract.