When Adinton detects your «Sources» thanks to utm_source, you can check the complete list here:
Once clicked, you’ll see the complete list of your sources. If you want to add a Cost of one Source, you should click on € symbol.
And here, you’ll be able to add the kind of cost of the source.
If your prefer these other methotds, just click: if you want to Upload your costs from a xls file or via Adwords’ API.