I think enterprise software agreements can often be negotiated.
In the case of GitLab, their pricing page has the usual easy ordering buttons for each pricing tier, but the $99 tier button also has a prominent "Contact Sales" link right below the button. https://about.gitlab.com/pricing/
Once you're already paying sticker price, and have invested in using it (i.e., moving to a competitor is a lot of work), your negotiating position will be different, but the vendor can still lose the account, if customer is unhappy enough to eat the moving costs.
