I'm not questioning your findings, but I wonder why an RN who took the time and expense to become a paralegal would want to work cheaper than a LNC? Are you sure they're using RN/Paralegals or just paralegals?
Perhaps its a matter of educating the attorneys in your area about the value a legal nurse consultant provides? There's an article by Vickie Milazzo that may help explain the difference and the great value legal nurse consultant offer to an attorney's practice:
Certified Legal Nurse Consultant's Analysis Spurs Record Settlement