I believe that gradually, with your explanations, I begin to understand your request ...
In case you use the scale module, you use the money module and therefore jOpenSim PayPal.
In this case you have a choice jOpenSim Paypal Transaction List.
This should answer your request ...
Now if you say "yes, but I do not want to install jOpenSim PayPal" then there ...
I still do not understand why you have this "?item=xxx" and this custom link seems to not work and not be enough. Normally this should be fine, right?