I'll help out here.
First thing - no such thing as a Class III weapon. Class III is a tax bracket. The phrase "Class III dealer" does not mean "Dealer in Class III items" it means "Taxpayer, Class 3"
Just like the clip v magazine debate - what's wrong is wrong.
Second - http://www.subguns.com/c2c3/c2c3.htm
I'm not on the list. In a few years, I expect to be - but reputation comes with time.
I can't speak for everyone but there are many that are part of the NFA business community have their FFL/SOT so they can goof around with post samples.
Read: They don't need your business nor do they care. They have to be running a business according to ATF but there's no federal law that says they have to be doing it very well.
Personally - I always tell my customers what saves them money. I turn trades down all the time because it is much more efficient for a customer to sell their gear themselves. I had 4 machinegun evaluations this week and I told the owner that for me to get involved with F4's - my standard rate is sizeable. If they want to do a F4 direct to the new owner, they can do that. I agree with you in that there is a sin of omission when they say you HAVE to clear through an FFL/SOT.
Hope this helped.
FFL/SOT Melbourne, FL - Sales by appointment. firstname.lastname@example.org
Sig Sauer Stocking Dealer
Silencerco Stocking Distributor