Well, the first thing to do is find the organization which stands to gain financially from the sale, and politely but firmly, issue a cease and desist.  Put them on notice that they are gaining financially from a copyright violation, and that you intend to take whatever measures are necessary to stop the infringemnet.

A lawyer can't do much more than that at this point anyway, and you can write a much less expensive notification yourself.

Before any legal action can be taken, you have to issue a notice of infringement.

Attorneys will tell you that your copyright, trademark, etc. are only as strong as you ability to protect it.