Hi opensimeule
There is a new component coming out soon, called "jOpenSimPayPal" that is doing exactly what you ask for
It will depend on an installed jOpenSim of course (new version 0.2.7 ... also beeing published soon). It is already installed here at jopensim.com currently still running in sandbox mode, but we plan to go live with it on saturday, 1st of june.
Depending on the results of the first few days, I will release this component for free downloading probably 1 or 2 weeks later (as soon as I have solved some minor cosmetic issues)
Greetz
FoTo50