I don’t think Dual Spec is really a good solution. It potentially creates enough of a change that it could affect gameplay for many people, and it would require relatively significant coding changes.
A different approach, such as reducing respec fees to max-out at say 50 silver, like they did on the Beta could help to remove the discouragement that a 50 gold respec fee seems to have, and also (depending on how the codebase has been developed) may not even require any coding changes, just a configuration setting.