Core build up and crown following root canal

[jdiese04]

I am 24 years old and have recently had a root canal on my #2 tooth, the last molar in front of my wisdom tooth. Because of the amount of decay in the middle of the tooth, the endodontist removed a lot of the middle and placed a temporary crown. In order for my dentist to place a permanent crown on my molar, he said a "core build up" is required, which jacks the price up to $650 total. Is this normal for permanent crowns?

[jdiese04]

The root canal was $400- then the core build up and crown will be $650. Im not concerned about the price- I just want to make sure the core build up is necessary?

[JawProblems]

650 total for the root canal, core build up, and a crown?  If that's the case it the cheapest I've ever heard.  I'm having my root canal and crown done for 700 which I believe is already very cheap.