Our payment gateway is through RBS Worldpay, Ive set Analyitics up to tell me when a goal has been completed when someone comes to the thank you page after checkout but is there any way to report how much a sale is. So if somone buys a product for £20 it will tell me that. This way I can judge how much we make from Google Adwords compared to what we spend?
You can do that. Its a very useful feature to optimize where to spend your ad campaign dollars. You need to enable e-commerce feature for analytics: http://www.google.com/support/analytics/bin/answer.py?hl=en&answer=55528 Then put in these analytics code. Which you can track which products (including its SKU and name), and how many were sold, each invoice's value, how many visits before the visitor made the purchase etc: http://code.google.com/apis/analytics/docs/tracking/gaTrackingEcommerce.html