Motive is an unknown. Perhaps not outright dishonesty present, but surely greed. Heck, some makers are just winking as they half-heartedly pretend to play the game of protecting their authorized dealers. Good authorized dealers may be small. They may work hard to educate & represent the goods & need to keep solid margin. When greedy, makers can unload huge quantities for millions, & hey, they've moved goods quickly.
Through shipment records & the ability to create variations, different model numbers & certainly serial numbers, makers can usually tell where the flow came from. If serial numbers were filed off or altered, you know no US warranty will be extended.
The WWW has made international contacts easy. Could I find, say, a Singapore distributor of goods intended for the Asian market, perhaps made to lesser standards because of international price pressures, willing to ship me thousands of units for a quick sale? Heck yeah. Well, at least probably. Substantial money & just some mental ability helps.
When young I took a couple chances. Like a typewriter with one page xeroxed English instructions (Japanese - at least I think) was enclosed. Service? Not a chance. Anything I might be more inclined than others to chance? Yeah, maybe like a Canon camera as they're rather clear cut, identifiable & relatively free from disasterous operation failures.
Then there's categories like "B" stock, blems, refurbs. Do you really know what you're getting? Often not. There is legitimate & otherwise.
And always, who are you dealing with? Try to conceal their real location? Cheap rental storefront somewhere around Brooklyn? Don't take chances on strangers any more than naive faith about anything & everything on the internet. A slim chance of me sticking my neck out of any dealer without solid customer feedback on places like ResellerRatings.com, Amazon, epinions or shopping.com. Sorry that leaves out anyone brand new to the business, but they've absolutely no track record.
It's still a let the buyer beware world. Risk is real. Sound too good to be true? Well...