Showing total of amount in view
Sounds like a job for Views Calc.


  This module adds simple calculations to a views table. Requires the
  Views module.
  
  You can SUM, AVERAGE, COUNT, MIN, MAX, or AVG selected columns. A plug
  in theme makes the view look more spreadsheet-like (right justifies
  numeric fields, shades calculated columns and rows, and underlines
  calculated rows).