Originally Posted by Barabaika
I wonder how it is possible.
For example, there are two bike companies that have $300 bikes.
How can one company use good components and another bad if they both buy them from Shimano? I understand if the second company uses noname components that can fail.
Shimano makes both good components and really cheap junk. It is possible that one company specs a slightly better cheap component for a bike in the same price range (for instance, Alivio instead of Acera).
You get what you pay for in most cases. My mountain bike, a single speed with no derailleurs and no rear suspension, would cost about $2500-3000 if you paid retail for it. I was working in a bike shop so I didn't pay full retail. I still paid a lot of money, and I couldn't get a deal on the frame which cost me $750. Was it worth it? It was to me. In truth, I could still have fun on a Redline Monocog 29er that cost $550 (the cheapest bike in the category) but it would be heavier, slower, more painful (no front suspension) and break more often.
A $300 bike has lots of cheap parts that will not last. You don't have to spend $2500 but $500-800 is a more reasonable price range for a bike that will be ridden regularly.