You can use Offer module if you want to add links manually to your product list
Use direct link on product page in "Product URL" field (without any affiliate network's parameters which are usually after symbol "?"). You should use deeplink in separate field. Read about deeplink here.
In example above, we used deeplink directly in field. But you can create global deeplinks and xpath for each domain. So, if your offer doesn't have deeplink field, plugin will use global settings.
You can also overwrite custom settings by global fields (global settings will have priority)
Price update for Offer module
This is only for advanced users. You must have some basic knowledge about XPath.