[rodent54]

I would suggest that rather than move "up" and out of testing they need to move firms.

Testing is a VERY different skill set to dev. While good tester have coding skills, and understand concepts like design patterns, most of their knowledge is in failure modes of systems (inc. software), and how to identify/prevent these. Often they have security or performance testing skills on the side. Almost always they have automation skills. If a company does not understand that these skills are as useful as a developer, or BA etc, then I suggest that the tester needs to move firms - from experience there a plenty of firms that do value these skills.