Tradekey & Alibaba Wholsaling - How to Use? Advice

Hi I currently dropship a niche product lets call its Widget, but my competitors who do dropshipping like me are creating their own brands and I have a suspicion they're just buying the products from China in wholesale with their custom packaging and reselling it to distributor here. Along with having exclusives that I can't sell.

I think they also custom designed their widget and sent it out to China for production, last year they had 1 Widget now they have 4 under 4 different brands. 2 of products I believe I can easily copy.

Over the next 12 months, I want to do the same, because if my competition is creating their own brands selling the same stuff along with the existing dropshiped products from manufactures from the United States, they're making more money, and might stop dropshipping the brands they do dropship and keep all their brands exclusive.

They're buying these Widgets for $10-20/unit, and then do one of two things.

1) sell to a distributor, who dropships (2/4 of the brands they have), the distributor then sells them for $40-$60/unit, which in turn I sell for $80-$100
2) keep 2 of the brands exclusive to themselves and sell on their own websites.

I don't understand how the existing manufactures lets them sell their own brands, I wouldn't sell to competition

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One of the brands their selling is very similar to what I've seen on TradeKey and Alibaba. I want to take the same product and repackage it under a my own brand, if that becomes successful, I want to design my own and manufacture it in China. Some of these products have patents so I'm limited to what I can design.

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Sooo...... the question out of all of this is

1. If their buying units for $10-20 how much are they selling to distributors who then offer the products for dropshiping?
2. How do I find trusted suppliers?
3. What scams should I look for
4. Are their other services other than TradeKey and Alibaba I can use?

2 Years ago I got burned by a supplier from one of these sites selling iPhones for wholesale, They played me well, I tried to do my due diligence the best I knew at the time, because I had a continued communication for over 2 months but as soon as I western unioned the money they stopped talking to me.

I've dealt with one Chinese wholesale successfully before 5 years ago, but it was on a very limited case. and these days scams are rampant.

its only after when I checked out their address and googled it, it was linked to a dozen of similar of the same looking, same selling websites. Learned my lesson.

ADVICE? Anything you can advise me on would be greatly appreciated.