He who buys cheap pays twice
A lot of what you see cheap on line from places like Evil pay and Craigs Luck are the stuff that has failed the quality control of the people who get stuff made in China.
In the USA that stuff goes in the recycle bin usually after being smashed so it has to be recycled.
In China it gets sold on the local market as "part that fits Abecef " because the margins are so low the factory can not afford to trash anything.
These defective parts go through a number of hands then end up in the retail parts system and get sold to people like you who just chalk it up to experience then go out & buy another.
For which Ifool Yoo and his extended family thank you gratefully.
Two little tests
1) check the "other items" list.
If it comes up with an inventory bigger than Walmart they are a trading company buying whatever they can cheap and flogging it off at 2 to 20 times what they bought it for.
If it come up with nothing but related items then there is a better than average chance it is a wholesaler or factory outlet.
2) is the product branded ?
If you make good stuff you want every one to know where it came from so you get repeat customers.
If it is garbage you don't want any one to know where it came from so you can fool a lot more cheapskates.
Classic example.
Hurtzl sell Stihl 070 ( lightning ) saws as an "full engine repair kit" for around $ 300 + freight
These kits are good and when assembles & fitted with a good bar will give you a good saw, a little down on power on the original 070 and not as robust.
You can buy the "same" kit from around 30 other places for as low as $ 100 including freight but usually the pars do not fit properly and many times the was will not work after assembly because it is all of the reject parts.
If you are wondering why they are sold as kits it is because the 070 does not have a chain brake so is illegal to sell in most countries