$100 dollars to geocache in national forests! Just in Georgia! ...Unless I've misunderstood you, 'Just in Georgia!' isn't nice to say. Georgia is gorgeous from what I've seen. That aside. ...I think you did misunderstand. As I read Luckless' post, 'just in Georgia' related to the fact that the permit was only good in Georgia, rather than regional or national.
Of course, I'm a little confused as to what the permit allows. If it is $100 per cache, that's pricey. If it covers as many caches as can be placed in Georgia parks and doesn't include an individual approval process, that may be a very good deal.
I understood "blanket permit for geocachers" to mean a permit to geocache, probably for a period of time like a year or 5 years. Sounds like a hunting or fishing license. I looked at the GA Geocaching Guidlines on the GGA website (here) and didn't find this information. They do mention a permit, but there is no information on how to get one, what it permits or how much it costs. I had hoped that the GA Geocachers Assn. website would have more details. Maybe I just missed it.
We're passing through GA in two weeks and planned on geocaching. I never even considered that there may be laws governing this. I guess I should to check NC, SC and FL too.