Your financial analysis is more honest than most pre-law students'. A few additional factors:
For: Your 5 years as a paralegal is a HUGE advantage. You understand how law firms actually work, which cases are good, and how to manage workload. You'll outperform most classmates in practical skills from day one. Firms value this experience.
Against: The legal market is contracting in some practice areas due to AI tools (document review, basic research, contract analysis). The areas growing are the ones requiring judgment, client relationships, and courtroom skills — which happen to be the ones your paralegal experience prepares you for.
Practical advice: Look into part-time evening JD programs. Several ABA-accredited schools offer them. You'd keep your income, gain the JD in 4 years instead of 3, and potentially have your employer contribute to tuition. The opportunity cost drops dramatically.