To auction temple hair, you have to be a big company and should be able to risk huge amount of money. Average "cost of auction" for a temple can easily cross half a million US dollars. So not every company in India has wholesale access to this grade of human hair.
Most of the companies do procure non remy hair which is very cheap;1/10th of the cost of temple hair. Most importantly, it can be bought in very small quantities and the risk factor is very low. So 90% of hair companies in India sell cheap non remy hair.
And the case with China is pretty simple. 100% of hair from China is non remy / synthetic / processed animal hair / a mix of them. They have no access to temple hair.
Procuring temple hair is tough yet keeping the hair remy until it's shipped is much more complex as well.
Most of the companies do chemical processing all through the steps. For example, nit and lice picking is done using chemicals and it oddly takes minutes to remove nits from 10 Kilo/100 bundles of hair. Use of chemicals spoils the hair and makes it brittle and rough. Moreover the chemicals damage the cuticles and so the shine and beauty of natural hair is lost.
But we at DHWARAK INDIAN HAIR use painstaking and time consuming manual process; on an average, a person picks 7 to 10 bundles per day. We have no chemical approach at our factory. And this is why our bundles look healthy and the natural shine is preserved.