Jack what procedure did you have done on the tooth after the root canal failed last year...an apicoectomy? If the guy who did the apico is also the one doing the implant he should credit the fee you paid towards the implant.
I can't comment too much on the fees since they are out of my area of expertise.
Jack implant failures are much higher in smokers, and in general higher in the maxilla (upper jaw) than the mandible. I would discuss this with whoever is doing the procedure.
To those who face the decision of having a root canal and crown done in the future, give strong consideration to having the extraction and implant. Even the best root canals can fail over time, it's still a tooth which can get new decay under the crown. When you get a titanium implant and it integrates into your bone that son of a bitch isn't going anywhere. The crown may fracture at some point but should last a long time. Since there's no natural tooth structure there, no way to get a new cavity on it, etc.
Jack not like I know you but from your personality posting on here I think the flipper will drive you nuts after a while. You are going to be much happier chomping into that ribeye with the implant than the flipper.