​How much are the costs for fixing teeth that don't have enamel or dentin?

The best way to fix teeth without enamel is to crown (also known as cap) all of them.  This would be like veneering all of your teeth and cost you about $1200 to $1800 per tooth, depending on your region.  Teeth can generally be prepped and crowns placed in one appointment.  I would highly recommend scheduling a consult with a cosmetic dentist to discuss the price and timeline of care. 

You are probably a candidate for a full mouth reconstruction that establishes the correct occlusal planes, vertical dimension and 3 dimensional positioning of the jaws.  You work will probably be quite extensive and I would suggest beginning with provisionals to establish the ideal before switching to porcelain or ceramic.  It will be expensive if done correctly.  If you have a genetic disease that caused the lack of enamel you may get excellent medical coverage.  A diagnosis would be the first step and you might want to consult a genetic counselor.