Interpreting the expression «Worth the price» from Pinegulf is not immediate.
Surely, as rvbissell wrote nearby, there are contributions around of negative value - though maybe rarely in technical publications of this kind.
If you want to donate to Carlo Occhiena, information does not seem immediately available, but his personal website - carloocchiena.com - contains his E-Mail address at the bottom of the JS generated typing, linked at «mi puoi scrivere una mail».
...