We have had our programmer try to implement dynamic revenue tracking (using the new google global site tag/snippet system) which is supposed to track the purchase amount from all sales resulting from clicks on adwords ads.
The new google global site tag system has been used however at this stage it seems to record each conversion as 1 rather than the actual purchase value in both google shopping and website sales.
You will need to be have expertise in Adwords/Analytics and Oscommerce (PHP). You will need to modify the code in the website pages (if necessary) and/or amend any adwords/analytics settings as well as check that any new code is accurately recording revenue amounts.
Under the older system (non global tag) we were successfully tracking revenue, but we are informed google are making that system obsolete in favour of global site tags.