Ebay.. Whats the deal?

Where do sellers on Ebay come up with the "new in the box" products they are selling in quantity? For example, where does a seller come up with quantities of "new in the box" Raytek MT-4s that he can sell on Ebay and make a proffit worth selling them at that price for? It doesn't seem like their customers are unhappy, judging by the close to 100% satisfaction ratings listed for most of these types of seller. Something seems wierd to me. Anyone know the inner workings of this type of stuff?

Woops. forgot too include the price these guns are going for....around 46.oo

That's a question I have often wondered. Another example is I have been looking for a set of saddlebags for my bike. At this time I'm not ready to put 4-500 in a high quality american made set, so I was looking at some asian made ones to get me by for a year or two.
I had decided to pick up a set at a local bike shop for $169 a set. I ran a quick search on ebay and found the exact same bags with the tags still attached for $89. I ended up buying a slightly smaller set brand new with tags, which looks better on the bike, for $57 shipping and all.
I can see in certain circumstances where someone operating out of a spare room in the house could undercut prices considerably by eliminating all the overhead and buying in quantity, but there's even a limit to that.
The local bike shop for instance has excellent prices on leather, even cheaper than the outlet stores who sell the same products.

I know how some of the sellers do it, the ones selling off brands and refurbished products, but the new in the box name brand stuff I don't get.
I would bet in a few instances stolen goods are involved, but generally speaking quantities of stolen merchandise will be limited and some of the sellers have an apparently endless supply and sell continuously over the long term.