hi,
it is not an urban legend, people do it here, but i have no real numbers. most people with the means consider Leman, QSI, the Waldorf School or Chengdu International. The prices are of course a big factor here. Internationally flavored schools are at least 3000RMB a month, and can be much more. Local schools are basically free, with some small costs related to books and other basic fees. And the Chinese language immersion issue is big with people going local. The big drawback is that Chinese themselves feel their edu system is very bad, and foreigners tend to agree. I think finances play a big role, and the specific school you choose.