I have developed an extension and I am posting here for free.
An extension that will add a ‘Profit’ column in Orders grid showing profit per order. Configuration setting are provided for disabling the column and editing the column header.
Tested with Magento Community Edition 1.5, 1.6, 1.6.1, 126.96.36.199, 1.7 and Magento Enterprise Edition v188.8.131.52
1. Install the extension from Magento Connect using the zip file.
2. Refresh the cache.
3. Return to Admin.
4. Go to Admin > System > Cache Management > Select All > Select Action ‘Refresh’ > Submit
5. Browser to Admin > System > Configuration > Order Profit
6. If 404 page found, than kindly log out from admin and login again and follow step 5.
7. Set Enable to ‘Yes’ (If set to ‘No’ the functionality will be disabled)
8. Click ‘Save Config’ to store the settings.
9. Browse to Sales > Order and you will be able to see the column
GitHub : Order Profit