You are doing a background check that requires three different agencies. You are required to do fingerprints and a photo. Those things cost time and money. I did some searching and could not find a estimate for how much each NFA background check costs, but I did find some small piece of information that raises my estimate of how much they cost: It is not a one time deal. You have to then support each NFA stamp by requiring approval for every transfer, ever time someone crosses a state line, every time they change address. So, unless you want to charge for all of that as well, it needs to all be factored into that original fee.
Those things are mostly automated and you can get them done relatively cheaply. We are talking tens of dollars, not thousands of dollars. You have to send in photographs and finger prints (generally taken at your local police/sherifs dept) when you apply for a stamp. You pay for this separately, it's inexpensive.
What you say about every transfer is correct. If you want to sell your NFA regulated firearm, the buyer has to go through the same process as you did previously, despite it being on the used market. This would be the same way that that used guns are sold currently, except for private sales in areas where background checks are not required (i.e. what people call the gun show loophole, which is really a private sales loophole). But yes, this would mean a full background check every time a NFA regulated weapon is sold.
As far as the state line thing, that only applies to certain NFA items. Specifically, it does not apply to suppressors and AOWs. Also, it's important to realize that this isn't a background check. It's literally a "permission slip" from the BATFE to allow you to move them from state to state.
I'm not trying to be a dick here, but what is your estimate based on? Thousands of dollars is ridiculous for a background check (yes, even from multiple agencies) in the age of computers.
I agree it is a good first step. It has a number of other provisions I think would help as well.
It makes the penalty for owning a NFA controlled item considerable higher than is current for any other firearm and with less burden of proof. Just having possession of a NFA controlled firearm with out proof of a permit is a felony with a $10,000 fine and 10 years in federal prison.
You can not sell or otherwise transfer a NFA controlled item with out ATF permission and a background check, basically all transfers of NFA controlled items is treated just like an original sell. It closes the gun show loophole and makes all grey markets into a black market.
You can not cross state lines with a NFA controlled item without written permission from the ATF.
You must always be able to provide proof of registration for any ATF controlled item on request. (want to carry a gun, you must carry it's registration papers as well)
Obliterating, removing, changing, or altering the serial number of a NFA controlled item is against the law.
Any violation of those things could carry a penalty of up to $10,000 and 10 years in federal prison, and the possibility of secondary charges that include of up to $500,000 fine and an additional 5 years in prison.
Agreed. Note, most of us with NFA weapons always carry copies of our paperwork with our weapons. I should also note that it is, in general, not required that you carry your paperwork with you, only that you can produce it upon request. It's just obviously easier to have a copy with you so that you can produce it if circumstances require it. I've never been asked to produce my documents for any reason.