I have to decide between root canal or extraction and implant, I have internal resorption of my molar.

My dentist believes tooth #30 has internal resorption. I was given antibiotics to treat the infection. Now I must decide if I should attempt a root canal, the Dr is not convinced the tooth is salvageable, won't know until it's opened up. Or I can extract it and get an implant which is not covered by insurance since it's "cosmetic' even though I only have one molar on that side and obviously need it to chew. It's very expensive. Should I get a second opinion to see if the tooth can be saved?