How much of hourly rate is fair for a PRN nurse job?

I’m an ICU RN who has 2 years of nursing experience and is going PRN in my current job. I work at a memorial Hermann community hospital and they’re offering me $1.50 more than my base pay. I think that much of an offer is too little since I will no longer going to be eligible for benefits. I was wondering what is your hourly pay rate if you’re working PRN at a hospital? I’m currently going to work at one facility and MICU only as PRN. Is it an unfair pay rate?