How $1,000 can create a smartphone brand to challenge Samsung

Walk through a metal gate, sidestep a pile of boxes, take an elevator to a floor of serviced offices and enter the latest battleground for Samsung Electronics Co.

In a small suite in Shenzhen, Guangdong province, Cathy Chang is helping clients from around the world create their own smartphone brand. Choosing from a menu of options akin to ordering a pizza, Shenzhen Zuoer Technology Co's customers can get into the handset business for as little as $1,000. No experience needed.

Zuoer is among the dozens of little-known Chinese companies that are tapping into a catalog of standardized components to build smartphones from $20 apiece. For a minimum order of 50 units, Zuoer assembles its own plastic outer shell with other manufacturers' LCD screens, circuit boards and batteries, helping any client anywhere take on Samsung in the $410 billion global mobile phone market in less than six weeks.