I have no objection to someone making a few quid for putting the f/w on but I do not agree with them charging such inflated prices because of the advice we give out.
I guess it's a tricky one.
There will be people out there who would like to take advantage of this freely-given work but do not have the technical ability/time/motivation/whatever to take what is available online and do it themselves.
So, as the work is freely available online it's just a market for those prepared to do it for others.
One way to give some sort of protection are the various models of public licence that require acknowledgement etc. and/or no commercial use. But that's possibly a bit OTT for those involved in doing the original work.
A bit of honesty by sellers might help, but why would they give away all the details of their sources in an eBay listing and potentially sabotage the effort they have made to understand and know how to apply the work of others.
"Standing on the shoulders of giants" I guess, or is it just plagiarism? Probably not, it's somewhere between.