I've had the opportunity to work in several different business sectors during my work life.  Wood product manufacturing, music store retailing, retail gift wares, retail jewelry to name some.  I've been in the janitorial industry now for 13 years and find it to be one of the most unethical and cut-throat.  There is a high percentage of illegal workers and most end-users could care less.  As your comments state, they are only interested in the final price.  We recently lost a large building where a new franchise in town cut our existing contract price by 40%.  We are due to check back as you also suggest.  It will be interesting to hear their comment about the new service.  

Also...there seems to be a trend for new medical facilities and surgi centers to outsource their janitorial services, since the in-house option costs them more.  Most medical facilities in our area are cleaned by companies that hire illegals and do not offer any health care benefits.  I find it interesting that the folks who clean these procedure and exam rooms each night, so patients have a safe place to be seen by a doctor, have no health care benefits of their own.  The medical profession is also interested in the lowest bid possible regardless of these facts.

i am working in one paper converting factory in China. Most of our sanitary paper is exported to US market and the main user is BSCs.

It is comment to meet the situation mentioned in post. There always someone quoted a much lower than yours, no matter how low we quoted.

Frankly, the cost of paper converting is clearer than other business. The general cost of pulp, paper can be easily found from internet. And the approximate cost of converting also can be calculated. So it is really funny to find the quotation even lower than the raw material cost.

From my experience, the most important point is to keep the  supply chain resonable, stable and reliable. It is hard to image one offer 1 USD today and 2 after several weeks and the receiving goods is good enough to make your mood "bungee jumping".

The recession is only partly to blame, unfortunately the problem started a long time ago with illegal immigration from both eastern Europe and Mexico/south/central  America.  No one got in trouble, none of our organizations did anything meaningful about it, and the government turned a blind eye forever.  To right the ship, every honest company has to be a whistle blower, every company from the same region should contact each other and band together to root out the poor and illegal companies.  Some of these companies are now quite large, doing over 10-20 million dollars a year in business.  If a company comes in more than 20% below a reasonable quote, check out the workers as they get dropped off, see how many show up, see if they speak english, drive a car, etc.  Then call the appropriate govt.  agency for help.  If enough companies perceive the problem and get pulled into the legal ramifications, things will change.