I know the other way around is basically the norm: how does one know the company, the seller, will actually provide the product after paying. But the prevailing culture, currently, is that companies in this regard are trustworthy and customers are not. It's a bit debatable but it makes sense.
Yes, I believe it does. These are highly specific brass tacks for making oval shaker boxes. There are very few manufactures of a proper #2 brass tack these days, so I would very much want to stay on the good side and any suppliers.
I think they said in their faq that twice they haven't been paid in 20 years or something like that. Their online "store" appears to be down right now–hopefully they are still in business.
edit: It appears John passed in 2023 :( https://blog.lostartpress.com/2023/02/07/john-wilson-1939-20...
Most people are not scammers and will pay simply because it's the right thing to do.If your margins are decent, you can just eat the loss to some scammers as the cost of doing business. Especially if there's no real resale market for your product.
With the "pay the bill later" it's entirely up to the recipient whether they decide to pay. Some will even just forget it with no ill intent.