If you are just an FFL (type 1 or 2) with an SOT (Type Class 3 aka dealer only) you do not need to pay the ITAR fee.
However, if you are a firearm manufacturer (type 7 or 10) with (Class 2 SOT) or not, than you will need to pay the ITAR fee regardless of whether you have ever or ever plan to export anything.
Are there folks out there who are Title 1 FFL firearm manufactuers and/or a FFL firearm manufacturer with a Class 2 SOT who have never paid the ITAR fee... sure, but they just have not been caught yet.
However, if you are a manufacturer FFL (type 7 or 10) and make anything that could be construed as a defense article that is on the United States Munitions List than by the letter of the law you need to register and pay the appropriate ITAR fee. (in most cases $1750 per year if memory serves correctly)
Hope this helps
James
Austin, Texas