Being tied-in to proprietary database software brings its own restrictions, you often have no choice but to payup in order to keep your database running. You might have to settle for sub-standard features, availability, or performance, which would be improved with a different set-up. If you actively choose vendor lock-in, you should be aware of your choices and the trade-offs that occur as a result. It is still desirable to have an exit plan in place, just in case.