If you have the capabilities to take it to market yourself, you`ll do better than a license agreement with a promotional company.
I would approach companies like Amazon, Barns & Noble and others directly to see if you can generate interest and potential orders before going to production. Given the high volume they do, it may be a pretty nice account.
They could upsell it to their customers, assuming it provides a greater value than a plastic or cloth bag and is priced reasonably.
Well it depends. If it`s a unique product with "WOW", then people will get excited. If it`s just another variation of something they already carry, then that`s a harder sell.
You say you have confidence that it will sell in B & N. Then I assume you know what the price point will be? With your "pretty high" domestic manufacturer quote, can you sell it to them with that price point and still make a profit? If not, then what?
Was just thinking about your bag. Not knowing what your proposed price point is, but you call your bag a promotional item. So I assume that it`s an inexpensive bag maybe like your nicer, yet typical cloth bag for shopping. But if you have filed for a utility patent, it must have some features to it that typical cloth bags don`t.
So, maybe it`s about how you position it. If you position it as a promotional item, that`s a very competitive market. But if you position it as a nicer bag with cool features you might be able to command a higher price point.
My strategy is "Always sell on features, never on price".