Refinance 30 year fixed @ 3.875

[Mark E]

Hey guys/gals, 

Refinancing my owner occupied property with cash call mortgage and they offered me a 30 year fixed at 3.875. I'm just curious is that a good rate during these times? They took the median fico score of 750. I have good income and 300k positive equity in the property and low debt to income. 

There is no closing cost and appraisal is covered. Should/Can I buy down the interest rate? I'll be talking to the processor tomorrow.