I think it's important to draw a distinction between a freelance consultant and one who works for a vendor as well.  For instance, if you purchase an application and want it setup you might hire an FTE for $60k (as in your example), or you might hire an independent consultant for $75-$100 per hour.  However, if you get a consultant from the application vendor (who theoretically should be the most experienced possible with resources no other consultant/employee would have such as a direct link to engineering) then you should expect to pay $175-$300 per hour.

Is it worth the extra cost for consulting?  I think so in many circumstances, but then again I'm a consultant so there's my bias.  However, I think that under most conditions I can easily churn out 3x the productivity of a good FTE doing the same work due to my experience.  Perhaps the more important thing though is that I'm much less likely to take a wrong turn down a dead-end in terms of development.  That not only saves me hours, but it could save an entire project team many weeks of re-work due to mistakes or wrong assumptions.

Another benefit mentioned earlier is a direct line to engineering.  If an FTE hits a bug or issue, maybe it'll get reported and fixed, but it could take months for a release.  If a consultant hits the same issue, it could be fixed by the end of the day.  That's not every bug naturally, but those connections count when the project is on a tight timeline.

Consultants vary greatly from person to person though even within a single consulting company/dept.  Get a good one an the extra cost is well spent.  Get a bad one and its money wasted.  Perhaps what is needed by clients the most is a mechanism to better guage the consultants they have.