I have my tooth decayed to the gum line. What should I do and how much it costs to replace total tooth.

The tooth has decayed completely. It will go for extraction if tooth structure is not left. Exrtraction will costs you starting from 500 to 700 replacing the lost tooth how is a big decision for you. There r many ways of doing it. Either the removable plate or the fixed bridge that takes support from the adjacent tooth or implant removable can cost you around 1500 bridge costing varies starting from 6000 to 10000 implant starts from 18000 to 25000 or 35000 depending on the brand.