Hi Taro,
Can you share the screenshot of your quotation form? I unable to find these (Estimated Cost & Estimated Profit) in OOB CRM. Are these custom fields.
To answer your questions about how to calculate, you have multiple options depending about the calculation you wanted-
1. Create a calculated field
2. Or you could use business rule and use formulas to set the values
3. Or, use workflow to set field values
4. or, use JavaScript for calculation
But like I said above, the option depend upon what is teh calculation you wanted on these fields.