Big Box Bicycles: How much do those frames cost to make?

I found on a Linkedin group called “Bicycle design and engineering” this interesting  information and my question is:  
Why would you buy or you don’t buy a bicycle like that?

Started by Michael Downes

I was wondering about those Big Box $100 'bicycles'. Does anybody have any insight into what percentage of the retail price is represented by just the frame? I ask because I noticed a wide range of frame styles from really basic diamond frames to complex 'full suspension' designs and yet there is not much of a price range. They seem (at least here in the States) to run from just under $80.00 to a maximum of $150.00. Compare that to the products in the IBD's where the price points cover a far greater range.

Adam Hunt - Depends a lot on landed costs. I had a friend of mine who was sourcing out Chinese made titanium frames and the cost for the frames and forks were far lower than you would expect.

Mike Flaherty  - Due to cheap materials and fast, lower quality welding these frames can run as low as $15. My old trading agent in Taiwan was telling me that he found a complete 21 speed mountain bike in China that was only $21 to make - complete with all components. It can get pretty crazy.

Bob Long  -  I have purchased several frames from several sources in China, ranging from $12-40$.
Complete bikes with Big Box type components from 35-80$ depending on the style and Qty. I had custom bikes made with custom colors, min order was 100-200 units.